CN114420549B - Method for bonding silicon dioxide surface and silicon surface at low temperature - Google Patents

Abstract

The invention provides a low-temperature bonding method for silicon dioxide surface and silicon surface. Set the first low temperature condition, and sink the bottom silicon dioxide on the bonded surface of the substrate through the thermal decomposition process of ethyl silicate to generate a wafer; activate the wafer through the electron cloud, wash it with deionized water, and introduce Hydrogen bond; bond the wafer and ordinary silicon chip after the hydrogen bond is introduced under a preset pressure, and anneal at a second low temperature after the bonding is completed to generate a bonded semiconductor product; the semiconductor product Conduct ultrasonic flaw detection and grinding test to judge the bonding result. The invention innovatively uses the silicon dioxide layer prepared by PETEOS at 250°C to 450°C as the bonding surface, without the need for 1000°C high-temperature thermal oxygen process and 1000°C high-temperature annealing process. It can greatly reduce the requirements for process machines, reduce energy consumption, and reduce overall costs. The most important thing is to create feasible process routes for many materials and products that cannot withstand high temperatures, and output reliable process effects.

Description

A method for low-temperature bonding of silicon dioxide surface and silicon surface

technical field

The invention relates to the technical field of silicon bonding, in particular to a low-temperature bonding method for a silicon dioxide surface and a silicon surface.

Background technique

At present, the current bonding process is mostly used for product pattern transfer or special reinforcement process. Among them, the silicon dioxide surface is more bonded to the silicon surface, but the traditional process is generally to perform a 1000°C thermal oxygen process on the bonding surface of silicon wafers or other materials to generate silicon dioxide, and then pre-bond with silicon wafers , and then undergo an annealing process at 1000°C to achieve complete bonding. The key to its bonding strength and quality mainly depends on the stress performance, curvature, roughness, and the conditions of the annealing process after the pre-bonding process of the two bonding surface materials of the silicon dioxide material and the silicon material during the pre-bonding process. , high requirements for process machines and high energy consumption.

Contents of the invention

The invention provides a method for bonding silicon dioxide surface and silicon surface at low temperature, which is used to solve the bonding process in the prior art. The key to the bonding strength and quality mainly depends on the silicon dioxide material and the The stress performance, curvature, and roughness of the two bonding surface materials of silicon materials, as well as the conditions of the annealing process after pre-bonding, have high requirements for process equipment and high energy consumption.

A method for bonding a silicon dioxide surface to a silicon surface at a low temperature, comprising:

Set the first low temperature condition, and sink the bottom silicon dioxide on the bonding surface of the substrate through the thermal decomposition process of ethyl silicate to generate a wafer;

Activating the wafer through an electron cloud, washing it with deionized water, and introducing hydrogen bonds;

Bonding the hydrogen-bonded wafer and ordinary silicon wafer under a preset pressure, and annealing at a second low temperature after the bonding is completed, to generate a bonded semiconductor product;

The semiconductor product is subjected to ultrasonic flaw detection and grinding test, and the bonding result is judged.

As an embodiment of the present invention: the method also includes:

Setting up a vapor deposition platform, and controlling the temperature of the vapor deposition platform to be between 250°C and 450°C;

setting a high-density plasma, and depositing silicon dioxide under the conditions of the high-density plasma;

After the deposition is complete, a wafer with a bonding surface is produced.

As an embodiment of the present invention: the ultrasonic flaw detection includes:

Infrared scanning is performed on one side of the bonded ordinary silicon wafer to obtain an infrared scanning image;

Carry out color recognition to described infrared scanning image in color space, judge whether there is color difference; Wherein,

When there is a color difference, it means that the bonding result is unqualified;

When there is no color difference, the bonded semiconductor product is scanned in three directions by an ultrasonic probe; among them,

The three-way scanning includes: performing direct-ray flaw detection from the ordinary silicon wafer surface, direct-ray flaw detection from the wafer surface, and lateral flaw detection from the bond;

According to the three-direction scanning, respectively acquire three reflected echoes of different ultrasonic flaw detections;

judging whether there are bubbles in the bonded semiconductor product according to the reflected echo;

According to the bubbles, the defects and corresponding defect positions are determined.

As an embodiment of the present invention: the grinding test includes:

Fixing the bonded semiconductor product between the first turntable and the second turntable according to the set preset indexing;

Set the rotation ranges of the first turntable and the second turntable, and control the bonded semiconductor products to move in opposite directions with the first turntable and the second turntable according to the lowest rotation value in the rotation range, and perform full-surface grinding , and when the torque values of the first turntable and the second turntable reach the maximum value of the rotation force range, stop the rotation, and judge whether the semiconductor product falls off, and when it does not fall off, reach the first bonding Intensity criteria and determine the grinding time for full face grinding; where,

When the entire surface is ground, the roughness of the front and back sides of the semiconductor product increases;

When the semiconductor reaches the first bonding strength standard, edge grinding is performed on the semiconductor product through the first turntable and the second turntable, and the edge grinding time is set to be the same as the entire surface grinding time, after the edge grinding is completed , to determine whether the semiconductor product falls off, and when it does not fall off, it reaches the second bonding strength standard,

After the semiconductor product reaches the second bonding strength standard, the semiconductor product is placed in a pulsed magnetic field, and the magnetic abrasive is used for cutting and grinding, and the bonded two sides of the bonded semiconductor product are ground Grind to a thickness of 100um~200um, judge again whether the semiconductor product has fallen off, and when there is no falloff, reach the target bonding strength standard.

As an embodiment of the present invention: the electronic cloud activation includes:

setting the first platform, and placing the wafer in the first platform; wherein,

The first machine is equipped with an oxygen increasing device and two laser emitting devices;

placing the wafer in an environment with high oxygen density;

setting the first laser beam and the second laser beam respectively, and projecting the wafer through the first laser beam to generate ion clusters;

A hollow electron cloud is generated by projecting the periphery of the ion bunch with a second laser beam.

As an embodiment of the present invention: the method also includes:

A second machine is set, and the wafer activated by the electron cloud is placed in the second machine; wherein,

The second machine is provided with a sterile water tank and an ion water washing tank;

The wafer after the electron cloud activation is first placed in the sterile water tank for 1H soaking;

After the immersion, the ion water washing tank is used for washing with ion water until hydrogen bonds exist in the wafer after the activation of the electron cloud.

As an embodiment of the present invention: the method also includes:

Set up the bonder; where,

There is a vacuum chamber and a normal pressure chamber in the bonding machine;

Place the hydrogen-bonded wafer and ordinary silicon wafer in the bonding machine, and set the pressure of the bonding machine to be between 60KN and 120KN.

As an embodiment of the present invention: performing annealing at the second low temperature includes:

Put the bonded wafer and ordinary silicon wafer into an oven, and set the temperature of the oven to be between 300°C and 500°C;

According to the oven, annealing is performed to produce a bonded semiconductor product.

As an embodiment of the present invention: the method also includes:

Carrying out deep silicon etching and thermal oxygen treatment on the upper surface of the silicon wafer;

Thinning the upper surface of the silicon wafer after thermal oxygen treatment, and then etching the top silicon on the upper surface;

The lower surface of the silicon wafer after top silicon etching is thinned and desiliconized, and the oxide layer is removed to obtain the target silicon wafer.

As an embodiment of the present invention: the method also includes:

providing a gas mixture, and installing electrodes on said gas mixture through which an electric field is applied;

A plasma is generated by charged particles colliding with gas molecules of the gas mixture according to the electric field; wherein,

The strength of the electric field is determined by the voltage of the electrodes, and the velocity of the charged particles is determined by the strength of the electric field.

The beneficial effects of the present invention are:

The invention innovatively uses the silicon dioxide layer prepared at 250°C to 450°C as the bonding surface by using PETEOS (thermally decomposing ethyl silicate under high-density plasma conditions), without the need for a high-temperature thermal oxygen process at 1000°C , and there is no need to undergo a high-temperature annealing process at 1000°C in the follow-up. It can greatly reduce the requirements for process machines, reduce energy consumption, and reduce overall costs. The most important thing is to create feasible process routes for many materials and products that cannot withstand high temperatures, and output reliable process effects.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and appended drawings.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a flow chart of a method for bonding a silicon dioxide surface to a silicon surface at a low temperature in an embodiment of the present invention;

Fig. 2 is a defect display diagram of ultrasonic flaw detection in an embodiment of the present invention;

Fig. 3 is a non-destructive display diagram of ultrasonic flaw detection in the embodiment of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Example 1:

As shown in accompanying drawing 1, the present invention is a method for low-temperature bonding of a silicon dioxide surface and a silicon surface, comprising:

Set the first low temperature condition, and sink the bottom silicon dioxide on the bonding surface of the substrate through the thermal decomposition process of ethyl silicate to generate a wafer;

Activating the wafer through an electron cloud, washing it with deionized water, and introducing hydrogen bonds;

Bonding the hydrogen-bonded wafer and ordinary silicon wafer under a preset pressure, and annealing at a second low temperature after the bonding is completed, to generate a bonded semiconductor product;

The semiconductor product is subjected to ultrasonic flaw detection and grinding test, and the bonding result is judged.

The working principle of the above-mentioned technical solution is: the present invention is an innovative method. Compared with the prior art, the present invention does not need to be bonded at a high temperature of 1000°C. Therefore, for a large number of materials that are not resistant to high temperatures, the present invention The bonding method is more suitable. There is also low-temperature bonding technology in the prior art, but the low-temperature bonding in the prior art is prone to unstable and unpaired chemical bonds when bonding these chemical bonds. It is easy to become healthy, but the requirements for the environment are relatively high, and the flatness and cleanliness need to reach a very high level, and the easiest environmental condition to achieve this very high level is vacuum, but in a vacuum state, the activation of the bonding surface Not good, hard to bond.

Therefore, the traditional bonding process is still through high-temperature bonding, by performing a 1000°C thermal oxygen process on the bonding surface of silicon wafers or other materials to generate silicon dioxide, and then pre-bonding with silicon wafers, and then undergoing 1000°C annealing process to achieve complete bonding. The key to its bonding strength and quality mainly depends on the stress performance, curvature, roughness of the two bonding surface materials of silicon dioxide material and silicon material during the pre-bonding process, and the conditions of the annealing process after pre-bonding.

However, the high-temperature process is not suitable for some product requirements, such as special structural products containing cavities or heat-sensitive materials, and the high-temperature process consumes a lot of energy overall and requires high hardware requirements.

中的扩 散不明显，而

团可以破坏桥接氧原子的一个键使其转变为非桥接氧原子，从而实现更 好的键合，而在高温状态下，键合的临近原子之间相互反应，产生共价键，使得键合完成，这 也是最主要的工艺。 In traditional work 1, the main effect of high temperature is that when the silicon-oxygen bond is formed, the water generated

The diffusion in is not obvious, while

The group can break a bond of the bridging oxygen atom and turn it into a non-bridging oxygen atom, so as to achieve better bonding, and at high temperature, the adjacent atoms of the bonding react with each other to generate a covalent bond, making the bonding Finishing is also the most important process.

中的扩散明显，是为了实现等离子体表面 的活化，现有工艺主要是通过高温进行活化，但是本发明是通过电子云进行活化，也达到了 高温氧化使得等离子体表面的活化的效果。另外，现有工艺会通过在增加悬挂键方面，主要 是基于等离子体表面的活化，然后基于化学溶液生成非桥键的羟基，但是本发明通过去离 子水洗，引入氢键，也到了现有技术的效果，相对于现有技术本发明更加的简单。在键合面 的洁净度上，本发明高密度电浆活化，就可以通过电浆的作用，对键合面可能存在的污染物 通过电浆除杂，电浆通过大量的电子轰击污染物，达到较高的清洁度，同时电浆还具有蚀刻 作用，达到一个较高的平滑度。去离子水的作用就像海绵一样。它吸收污染物和颗粒容易， 并清除积极。其纯度促进空化气泡在超声波清洗机的形成。它是一个不同的清洗剂,除去的 宽范围内的部分污染物，实现双重去除污染物，达到真空状态下的高效除尘结果。 However, the present invention breaks this high-temperature situation. The present invention prepares a silicon dioxide layer as a bonding surface in a high-density plasma, because the purpose of thermal oxidation is to allow water to

The obvious diffusion in the plasma is to realize the activation of the plasma surface. The existing technology is mainly activated by high temperature, but the present invention is activated by electron cloud, and also achieves the effect of high temperature oxidation to activate the plasma surface. In addition, the existing process will increase the dangling bonds, mainly based on the activation of the plasma surface, and then generate non-bridging hydroxyl groups based on chemical solutions, but the present invention introduces hydrogen bonds through deionized water washing, which also reaches the existing technology Compared with the prior art, the present invention is simpler. In terms of the cleanliness of the bonding surface, the high-density plasma activation of the present invention can remove impurities that may exist on the bonding surface through the plasma, and the plasma bombards the pollutants with a large number of electrons. To achieve a higher degree of cleanliness, while the plasma also has an etching effect to achieve a higher smoothness. Deionized water acts like a sponge. It absorbs pollutants and particles easily, and removes aggressively. Its purity promotes the formation of cavitation bubbles in ultrasonic cleaners. It is a different cleaning agent, which removes part of the pollutants in a wide range, realizes double removal of pollutants, and achieves high-efficiency dust removal results in a vacuum state.

Finally, in terms of bonding, the prior art is mainly realized by heating, and temperature is the key function of bonding, while the present invention is annealing at a second low temperature under a preset pressure. Compared with the prior art, the present invention requires a bonding machine, and at low temperature, pre-bonding is performed first, and then the bonding is realized through an annealing process.

The beneficial effect of the above technical solution is: the invention innovatively uses the silicon dioxide layer prepared at 250°C~450°C as the bonding surface by using PETEOS (thermally decomposing ethyl silicate under high-density plasma conditions), without Perform a high-temperature thermal oxygen process at 1000°C, and there is no need to undergo a high-temperature annealing process at 1000°C subsequently. It can greatly reduce the requirements for process machines, reduce energy consumption, and reduce overall costs. The most important thing is to create feasible process routes for many materials and products that cannot withstand high temperatures, and output reliable process effects.

Example 2:

As an embodiment of the present invention: the method also includes:

Setting up a vapor deposition platform, and controlling the temperature of the vapor deposition platform to be between 250°C and 450°C;

setting a high-density plasma, and depositing silicon dioxide under the conditions of the high-density plasma;

After the deposition is complete, a wafer with a bonding surface is produced.

The working principle of the above technical solution is: the present invention can deposit silicon dioxide at a low temperature to form the first bonding surface through the vapor deposition platform, and the reason for setting between 250°C and ~450°C is the first to reach A low temperature environment, but not a particularly low temperature, which will cause the silicon dioxide layer to fail to form. But there is also a precondition to be set, which is high-density plasma. The main function of high-density plasma is etching, but in the present invention, it replaces the need for high-temperature treatment in the prior art to realize the role of bonding surface polishing.

The beneficial effect of the above-mentioned technical solution is: compared with the prior art, the present invention adopts silicon dioxide deposition and high-density plasma treatment when forming the bonding surface. Compared with the prior art, the polishing effect is better, and the Get a smooth bonded surface.

Example 3:

As an embodiment of the present invention: the ultrasonic flaw detection includes:

Infrared scanning is performed on one side of the bonded ordinary silicon wafer to obtain an infrared scanning image;

Carry out color recognition to described infrared scanning image in color space, judge whether there is color difference; Wherein,

When there is a color difference, it means that the bonding result is unqualified;

When there is no color difference, the bonded semiconductor product is scanned in three directions by an ultrasonic probe; among them,

The three-way scanning includes: performing direct-ray flaw detection from the ordinary silicon wafer surface, direct-ray flaw detection from the wafer surface, and lateral flaw detection from the bond;

According to the three-direction scanning, respectively acquire three reflected echoes of different ultrasonic flaw detections;

judging whether there are bubbles in the bonded semiconductor product according to the reflected echo;

According to the bubbles, the defects and corresponding defect positions are determined.

The working principle of the above-mentioned technical solution is: after the bonding is successful, the most important thing of the present invention is to perform detection. The method adopted by the present invention is ultrasonic flaw detection, but before the ultrasonic flaw detection, the present invention firstly adopts infrared scanning, because silicon can Through infrared, so when infrared scanning is used, it is possible to timely divide the places with poor bonding effect through color differences. However, infrared scanning can only find large defects, for extremely small bubbles, or The place where the color difference is not large can not be found, so the present invention uses ultrasonic flaw detection again. After bonding, three-way ultrasonic flaw detection is carried out from the top, bottom and side surfaces of the semiconductor. In this way, if the three directions are all It is found that there is a flaw at a certain point, and if there is a flaw, it must be that the bonding effect is not very good. The results of ultrasonic flaw detection are shown in Figures 2 and 3. In the prior art, there is a bonding method that realizes the natural frequency by ultrasonic waves, but it is a completely different technical solution from the flaw detection by ultrasonic waves in the present invention.

The beneficial effect of the above-mentioned technical solution is: the present invention detects the flaws of the bonded semiconductors through an innovative double screening method, and judges whether the bonding effect is appropriate. Compared with the prior art, the present invention not only achieves bonding, but also Find post-bonding defects.

Example 4:

As an embodiment of the present invention: the grinding test includes:

Fixing the bonded semiconductor product between the first turntable and the second turntable according to the set preset indexing;

Set the rotation ranges of the first turntable and the second turntable, and control the bonded semiconductor products to move in opposite directions with the first turntable and the second turntable according to the lowest rotation value in the rotation range, and perform full-surface grinding , and when the torque values of the first turntable and the second turntable reach the maximum value of the rotation force range, stop the rotation, and judge whether the semiconductor product falls off, and when it does not fall off, reach the first bonding Intensity criteria and determine the grinding time for full face grinding; where,

When the entire surface is ground, the roughness of the front and back sides of the semiconductor product increases;

When the semiconductor reaches the first bonding strength standard, edge grinding is performed on the semiconductor product through the first turntable and the second turntable, and the edge grinding time is set to be the same as the entire surface grinding time, after the edge grinding is completed , to determine whether the semiconductor product falls off, and when it does not fall off, it reaches the second bonding strength standard,

After the semiconductor product reaches the second bonding strength standard, the semiconductor product is placed in a pulsed magnetic field, and the magnetic abrasive is used for cutting and grinding, and the bonded two sides of the bonded semiconductor product are ground Grind to a thickness of 100um~200um, judge again whether the semiconductor product has fallen off, and when there is no falloff, reach the target bonding strength standard.

The working principle of the above-mentioned technical solution is: the bonding effect test of the present invention includes two types. In addition to the ultrasonic detection, the rest is to carry out the grinding test. The grinding is mainly to judge if the two bonded parts are separated after grinding. It means that the bonding effect is not good, and if it does not separate, it means that the bonding effect is good.

Because there is no fixed standard for grinding in the prior art, the main function of grinding is to thin the entire semiconductor product. For the test of bonding strength in grinding, it belongs to the incidental ability of the thinning process. The joint strength is very low.

Therefore, when the present invention combines bonding, we set the thickness grinding standard for the whole bonding product, and the best thickness in the market is between 100um and 200um. According to this standard, we judge whether the bonding is qualified through triple grinding, and at the same time achieve the ability of thinning and bonding strength testing.

In this process, we set up two turntables, and these two turntables will rotate within a certain range of rotation force. This range of rotation force is the maximum after the roughness increases with the grinding of the bonded semiconductor product. Test the strength, because the rougher it is, the greater the grinding force must be. The grinding torque range is obtained through multiple experimental tests. Based on the rotation force range, the first grinding is carried out to obtain the first bonding strength standard. When this bonding strength standard is reached, the highest strength of the test is already higher than all bonding test methods on the market. However, The existing test methods on the market are mainly thinning. The present invention makes it rougher. Relatively speaking, roughness is conducive to better bond strength testing, but it is not conducive to thinning and making it smooth.

After the first bonding strength standard is reached, there is only one test on the market, that is, the whole chip is ground, and the force is relatively uniform when the whole chip is ground. It is particularly good, so the present invention is provided with edge grinding, and this edge is generally the edge area where the depth of both sides of the semiconductor product reaches 30%. When the edge is ground, the force is only a point on the edge, and there is a pulling force on other parts. If the bonding strength is not high, it is easy to pull and separate. So this is the second bond strength test. When this bond strength is reached, the bond strength mark is already very high. At this time, it is necessary to deal with the rough and uneven state of the two surfaces during the grinding process. We use a pulsed magnetic field to grind the thickness through magnetic abrasives, and adjust the thickness by the way. Under the action of the pulsed magnetic field, these magnetic abrasives are evenly and synchronously ground along the magnetic induction line, and then can quickly reach the desired thickness. At the same time, horizontal grinding, along the magnetic induction line, can achieve synchronous grinding. For places with different levels, because they are all on the same magnetic induction line, the uneven places only grind the convex places. Of course, this magnetic field is a horizontal magnetic field that is considered to be set, not a circular magnetic field similar to an electromagnet. This horizontal magnetic field is composed of two symmetrical and parallel permanent magnets, with a horizontal central axis, forming a horizontal positive symmetrical magnetic field.

The beneficial effects of the above technical solution are: the present invention judges whether the bonding effect meets the standard through strong physical grinding means.

Example 5:

As an embodiment of the present invention: the electronic cloud activation includes:

setting the first platform, and placing the wafer in the first platform; wherein,

The first machine is equipped with an oxygen increasing device and two laser emitting devices;

placing the wafer in an environment with high oxygen density;

setting the first laser beam and the second laser beam respectively, and projecting the wafer through the first laser beam to generate ion clusters;

A hollow electron cloud is generated by projecting the periphery of the ion bunch with a second laser beam.

The working principle of the above-mentioned technical solution is: when the present invention activates the electron cloud, there are many ways to generate the electron cloud, but the most suitable method for the present invention is the laser-generated electron cloud, because the electronic cloud can be generated directionally for activation , so the present invention provides a high oxygen density environment by setting up the corresponding machine, and generates a hollow electron cloud through two different laser beams to realize the activation of the wafer of the present invention.

The beneficial effects of the above technical solution are: the present invention can realize wafer activation by means of laser. Compared with the prior art, the present invention is more convenient, not only can activate, but also realize directional activation based on electron cloud, and the activation is more comprehensive.

Embodiment 6:

As an embodiment of the present invention: the method also includes:

A second machine is set, and the wafer activated by the electron cloud is placed in the second machine; wherein,

The second machine is provided with a sterile water tank and an ion water washing tank;

The wafer after the electron cloud activation is first placed in the sterile water tank for 1H soaking;

After the immersion, the ion water washing tank is used for washing with ion water until hydrogen bonds exist in the wafer after the activation of the electron cloud.

The working principle of the above technical solution is: after activation, hydrogen bonds are generated. Compared with the methods in the prior art, the present invention is more convenient to generate hydrogen bonds. In the prior art, after high temperature activation, non-hydrogen bonds are generated through chemical solutions. The hydroxyl group of the bridging bond, the non-bridging hydrogen bond generated in this way must have certain problems in smoothness, and the sterile water of the present invention is first soaked, which will make the activated surface more moist, and then washed by ionized water , it is easy to form hydrogen bonds.

The beneficial effects of the above technical solution are: compared with the prior art, the present invention is more convenient, and more hydrogen bonds can be generated more quickly to achieve a better bonding effect.

Embodiment 7:

As an embodiment of the present invention: the method also includes:

Set up the bonder; where,

There is a vacuum chamber and a normal pressure chamber in the bonding machine;

Place the hydrogen-bonded wafer and ordinary silicon wafer in the bonding machine, and set the pressure of the bonding machine to be between 60KN and 120KN.

The working principle of the above technical solution is: when bonding, the prior art is direct bonding through a high temperature annealing process. However, in the present invention, a corresponding bonding machine is provided, and pre-bonding is performed through this bonding machine first, and a certain pressure is set to ensure the bonding effect through pressure.

The beneficial effects of the above technical solution are: compared with the direct high-temperature annealing bonding in the prior art, the present invention complicates the process, but after the present invention divides the process, the bonding is more convenient. Does not require high temperatures and is more suitable for many different materials.

Embodiment 8:

As an embodiment of the present invention: performing annealing at the second low temperature includes:

Put the bonded wafer and ordinary silicon wafer into an oven, and set the temperature of the oven to be between 300°C and 500°C;

According to the oven, annealing is performed to produce a bonded semiconductor product.

The working principle of the above technical solution is: the present invention performs bonding at a second low temperature after pre-bonding, but needs to be placed in an oven to achieve better annealing bonding by gradually increasing the temperature.

The beneficial effects of the above technical solution are: because the present invention performs pre-bonding in advance, during the annealing process, too high temperature is not required to realize the bonding.

Embodiment 9:

As an embodiment of the present invention: the method also includes:

Carrying out deep silicon etching and thermal oxygen treatment on the upper surface of the silicon wafer;

Thinning the upper surface of the silicon wafer after thermal oxygen treatment, and then etching the top silicon on the upper surface;

The lower surface of the silicon wafer after top silicon etching is thinned and desiliconized, and the oxide layer is removed to obtain the target silicon wafer.

The working principle of the above-mentioned technical solution is: for silicon wafers, the smoother silicon wafers are more effective when bonding. In addition, the bonding detection of the present invention is the same as the infrared scanning method and the ultrasonic method, and it needs to meet certain conditions to be able to To achieve detection, that is, the silicon wafer needs to be thin enough to enable detection, and the above steps are required at this time.

The beneficial effects of the above technical solution are: the present invention can better bond the silicon wafers through the pretreatment of the silicon wafers, making the bonding surface smoother, and can also meet the thickness requirements for final bonding detection .

Example 10:

As an embodiment of the present invention: the method also includes:

providing a gas mixture, and installing electrodes on said gas mixture through which an electric field is applied;

A plasma is generated by charged particles colliding with gas molecules of the gas mixture according to the electric field; wherein,

The strength of the electric field is determined by the voltage of the electrodes, and the velocity of the charged particles is determined by the strength of the electric field.

The working principle of the above-mentioned technical solution is: the high-density plasma of the present invention requires certain generation conditions. In the prior art, the gas mixture is often used to generate plasma, but high-density plasma is difficult to produce, so the present invention passes The electrodes apply an electric field, and the velocity of the charged particles is adjusted through the strength of the electric field, so as to achieve the purpose of generating high-density plasma.

The beneficial effect of the above-mentioned technical solution is: compared with the prior art, although the method and principle of the present invention to generate high-density plasma are simple, it is more in line with the applicable scene of the present invention. If there are electrodes on the two surfaces of the bonding In the case of the present invention, there is no need to apply electrodes, which saves the process.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (7)

1. A method for low-temperature bonding of silicon dioxide surface and silicon surface, characterized in that, comprising: Setting the first low-temperature condition, and depositing silicon dioxide on the bonding surface of the substrate through a thermal decomposition process of ethyl silicate to generate a wafer; wherein, The first low temperature is between 250°C and 450°C; The wafer is activated by the electron cloud, and washed with deionized water, and hydrogen bonds are introduced; wherein, The electron cloud activation includes: setting the first platform, and placing the wafer in the first platform; wherein, The first machine is equipped with an oxygen increasing device and two laser emitting devices; placing the wafer in an environment with high oxygen density; setting the first laser beam and the second laser beam respectively, and projecting the wafer through the first laser beam to generate ion clusters; generating a hollow electron cloud by projecting the periphery of the ion bunch with a second laser beam; Bonding the hydrogen-bonded wafer and ordinary silicon wafer under a preset pressure, and annealing at a second low temperature after the bonding is completed, to generate a bonded semiconductor product; wherein, The second low temperature is between 300°C and 500°C; Conduct ultrasonic flaw detection and grinding test on the semiconductor product, and judge the bonding result; Wherein, the ultrasonic flaw detection includes: Infrared scanning is performed on one side of the bonded ordinary silicon wafer to obtain an infrared scanning image; Carry out color recognition to described infrared scanning image in color space, judge whether there is color difference; Wherein, When there is a color difference, it means that the bonding result is unqualified; When there is no color difference, the bonded semiconductor product is scanned in three directions by an ultrasonic probe; among them, The three-way scanning includes: performing direct-ray flaw detection from the ordinary silicon wafer surface, direct-ray flaw detection from the wafer surface, and lateral flaw detection from the bond; According to the three-direction scanning, respectively acquire three reflected echoes of different ultrasonic flaw detections; judging whether there are bubbles in the bonded semiconductor product according to the reflected echo; Determining defects and corresponding defect positions according to the bubbles; The grinding tests included: Fixing the bonded semiconductor product between the first turntable and the second turntable according to the set preset indexing; Set the rotation ranges of the first turntable and the second turntable, and control the bonded semiconductor products to move in opposite directions with the first turntable and the second turntable according to the lowest rotation value in the rotation range, and perform full-surface grinding , and when the torque values of the first turntable and the second turntable reach the maximum value of the rotation force range, stop the rotation, and judge whether the semiconductor product falls off, and when it does not fall off, reach the first bonding Intensity criteria and determine the grinding time for full face grinding; where, When the entire surface is ground, the roughness of the front and back sides of the semiconductor product increases; When the semiconductor reaches the first bonding strength standard, edge grinding is performed on the semiconductor product through the first turntable and the second turntable, and the edge grinding time is set to be the same as the entire surface grinding time, after the edge grinding is completed , to determine whether the semiconductor product falls off, and when it does not fall off, it reaches the second bonding strength standard, After the semiconductor product reaches the second bonding strength standard, the semiconductor product is placed in a pulsed magnetic field, and the magnetic abrasive is used for cutting and grinding, and the bonded two sides of the bonded semiconductor product are ground Grind to a thickness of 100um~200um, judge again whether the semiconductor product has fallen off, and when there is no falloff, reach the target bonding strength standard. 2. The method for low-temperature bonding of a silicon dioxide surface and a silicon surface as claimed in claim 1, wherein the first low temperature condition is set, and ethyl silicate is passed on the bonding surface of the substrate The thermal decomposition process sinks the bottom silica, and the generated wafer also includes: Setting up a vapor deposition platform, and controlling the temperature of the vapor deposition platform to be between 250°C and 450°C; setting a high-density plasma, and depositing silicon dioxide under the conditions of the high-density plasma; After the deposition is complete, a wafer with a bonding surface is produced. 3. The method for low-temperature bonding of a silicon dioxide surface and a silicon surface as claimed in claim 1, wherein the method further comprises: A second machine is set, and the wafer activated by the electron cloud is placed in the second machine; wherein, The second machine is provided with a sterile water tank and an ion water washing tank; The wafer after the electron cloud activation is first placed in the sterile water tank for 1H soaking; After the immersion, the ion water washing tank is used for washing with ion water until hydrogen bonds exist in the wafer after the activation of the electron cloud. 4. The method for low-temperature bonding of a silicon dioxide surface and a silicon surface as claimed in claim 1, wherein the method further comprises: Set up the bonder; where, There is a vacuum chamber and a normal pressure chamber in the bonding machine; Place the hydrogen-bonded wafer and ordinary silicon wafer in the bonding machine, and set the pressure of the bonding machine to be between 60KN and 120KN. 5. The method for bonding a silicon dioxide surface to a silicon surface at a low temperature as claimed in claim 1, wherein annealing at the second low temperature comprises: Put the bonded wafer and ordinary silicon wafer into an oven, and set the temperature of the oven to be between 300°C and 500°C; According to the oven, annealing is performed to produce a bonded semiconductor product. 6. The method for low-temperature bonding of a silicon dioxide surface and a silicon surface as claimed in claim 1, wherein the method further comprises: Carry out deep silicon etching and carry out thermal oxygen treatment with the upper surface of described ordinary silicon chip; Thinning the upper surface of the silicon wafer after thermal oxygen treatment, and then etching the top silicon on the upper surface; The lower surface of the silicon wafer after top silicon etching is thinned and desiliconized, and the oxide layer is removed to obtain the target silicon wafer. 7. The method for low-temperature bonding of a silicon dioxide surface and a silicon surface as claimed in claim 1, wherein the method further comprises: providing a gas mixture, and installing electrodes on said gas mixture through which an electric field is applied; A plasma is generated by charged particles colliding with gas molecules of the gas mixture according to the electric field; wherein, The strength of the electric field is determined by the voltage of the electrodes, and the velocity of the charged particles is determined by the strength of the electric field.

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