Summary of the invention
In view of the foregoing deficiencies of prior art, it the purpose of the present invention is to provide a kind of wafer bonding method, is used for
Solve the problems, such as that product quality is low and low yield caused by the bubble generated in wafer bonding face.
In order to achieve the above objects and other related objects, the present invention provides a kind of wafer bonding method, comprising the following steps:
There is provided at least two panels wafer, the surface of the wafer includes silicon oxide layer;
Ammoniated treatment is carried out to the silicon oxide layer of at least a piece of wafer, to form ammonia on the surface of the silicon oxide layer
Base dielectric layer;
By the amino dielectric layer by the wafer bonding, to form the ammonia of supercriticality in the wafer bonding face
Gas.
Optionally, during being bonded the wafer, generating in the wafer bonding face has water, the state packet of the water
Include one of supercriticality and gaseous state.
Optionally, the method for forming the silicon oxide layer includes atomic layer deposition method, chemical vapour deposition technique and life in situ
One of regular way.
Optionally, the method for the ammoniated treatment includes magnetron sputtering plasma ammoniated treatment, inductively coupled plasma
One of body ammoniated treatment and DPN processing.
Optionally, the range for forming the temperature of the ammonia of the supercriticality includes 132.4 DEG C~350 DEG C of reaction, and
The range of reaction pressure includes 11.28MPa~20MPa.
Optionally, in the step of being bonded the wafer, further include the steps that tempering.
Optionally, plasma-activated processing and cleaning treatment are included the steps that in the step of being bonded the wafer.
Optionally, the working gas of the plasma-activated processing includes one of nitrogen and oxygen or combination;Institute
The used cleaning solution of the step of stating cleaning treatment includes in the cleaning solution of deionized water, the cleaning solution containing ammonia and hydrofluoric acid containing
It is a kind of.
Optionally, the ratio range of the area of the area and wafer bonding face for the bubble that the wafer bonding face is formed
Including 0.1%~1%.
Optionally, any of the above-described wafer bonding method includes being applied to preparation one of SOI and back-illuminated type CMOS.
As described above, wafer bonding method of the invention, have the advantages that by the silicon oxide layer to wafer into
Row ammoniated treatment, to form amino dielectric layer on the surface of silicon oxide layer, then by amino dielectric layer by wafer bonding, with
Wafer bonding face forms the ammonia of supercriticality, to reduce gas under conditions of lower reaction temperature and reaction pressure
Size is steeped, product quality and yield are improved.
Specific embodiment
Illustrate embodiments of the present invention below by way of specific specific example, those skilled in the art can be by this specification
Other advantages and efficacy of the present invention can be easily understood for disclosed content.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also based on different viewpoints and application, without departing from
Various modifications or alterations are carried out under spirit of the invention.
Please refer to Fig. 4~Figure 10 c.It should be noted that diagram provided in the present embodiment only illustrates in a schematic way
Basic conception of the invention, only shown in schema then with related component in the present invention rather than package count when according to actual implementation
Mesh, shape and size are drawn, when actual implementation each component kenel and ratio can arbitrarily change for one kind, and its component
Being laid out kenel may also be increasingly complex.
As shown in figure 4, the present invention provides a kind of wafer bonding method, comprising the following steps:
There is provided at least two panels wafer, the surface of the wafer includes silicon oxide layer;
Ammoniated treatment is carried out to the silicon oxide layer of at least a piece of wafer, to form ammonia on the surface of the silicon oxide layer
Base dielectric layer;
By the amino dielectric layer by the wafer bonding, to form the ammonia of supercriticality in the wafer bonding face
Gas.
The present invention carries out ammoniated treatment by the silicon oxide layer to wafer, to form amino medium on the surface of silicon oxide layer
Layer, then by amino dielectric layer by wafer bonding, to form the ammonia of supercriticality in wafer bonding face, thus lower
Reaction temperature and reaction pressure under conditions of, reduce bubble size, improve product quality and yield.
Specifically, the number of the wafer can be to be N number of, wherein N >=2, only need to ensure to need in N number of wafer
The surface for the wafer being bonded is the silicon oxide layer containing silicon oxygen bond (Si-O key), the specific number of the wafer
Herein with no restriction.
Such as Fig. 5, first offer semiconductor substrate, the semiconductor substrate includes silicon substrate 111, Yu Suoshu silicon substrate 111
Upper surface silicon oxide layer deposited 112, thus the silicon substrate 111 surface formed the first wafer 110 containing Si-O key.
Wherein, the method for depositing the silicon oxide layer 112 includes one of atomic layer deposition method and chemical vapour deposition technique, herein not
It is restricted.Such as Fig. 6, the second wafer 120 to be bonded is provided, second wafer 120 may include semiconductor substrate, described partly to lead
Body substrate includes silicon substrate 121, dielectric layer 122 and the silicon oxide layer 123 positioned at 122 surface of dielectric layer.The silicon substrate
121, metal line or device be may also comprise inside dielectric layer 122 and silicon oxide layer 123, herein with no restriction.The silica
The forming method of layer 123 includes atomic layer deposition method and chemical vapour deposition technique, and the silicon oxide layer 123, which also can be only, to be given an account of
Matter layer 122 is formed by the silicon oxide layer containing Si-O key through in situ synthesis, herein with no restriction.First wafer 110
Can also be without silicon oxide layer deposited 112 the step of, and in situ synthesis is used, in the surface shape of the silicon substrate 111
At the silicon oxide layer with Si-O key, herein with no restriction.
Then, ammoniated treatment is carried out to the silicon oxide layer 112 in first wafer 110, in the silica
The surface of layer 112, which is formed, has amino (- NH2) amino dielectric layer 130.
Specifically, the method for the ammoniated treatment includes magnetron sputtering plasma ammoniated treatment, inductively coupled plasma
One of body ammoniated treatment and DPN processing.The working gas of the ammoniated treatment includes ammonia (NH3).Fig. 8 a~8c, signal
The reaction mechanism schematic diagram of ammoniated treatment.Such as Fig. 8 a, when carrying out ammoniated treatment to first wafer 110, the oxidation
The Si-O key in silicon layer 112 is broken off.Working gas NH in the Si-O key being broken off and the ammoniated treatment3Knot
It closes, forms hydrogen-oxygen key (- OH) and amino (- NH2), such as Fig. 8 b~Fig. 8 c, contain to be formed on the surface of the silicon oxide layer 112
There is-NH2The amino dielectric layer 130.
It, can also be to the oxidation in second wafer 120 to be bonded as the further embodiment of the embodiment
Silicon layer 123 carries out ammoniated treatment, has amino (- NH to be formed on the surface of the silicon oxide layer 1232) amino dielectric layer.
Those skilled in the art select according to specific needs, herein with no restriction.Preferably to playing carrier function, containing compared with
First wafer 110 of few function element carries out the ammoniated treatment, in order to reduce the damage to wafer.
Finally, such as Fig. 7, by containing-NH2The amino dielectric layer 130 by first wafer 110 and described second
Wafer 120 is bonded, to form supercriticality in the bonding face 140 of first wafer 110 and second wafer 120
NH3。
As the further embodiment of the embodiment, the step of being bonded first wafer 110 and the second wafer 120
In, include the steps that plasma-activated processing and cleaning treatment.The working gas of the plasma-activated processing includes nitrogen
One of gas and oxygen or combination;The step of cleaning treatment, used cleaning solution included deionized water, containing the clear of ammonia
One of washing lotion and the cleaning solution of hydrofluoric acid containing.
Specifically, the effect of the plasma-activated processing is that the Si-O key is broken to form silicon dangling bonds, it is described
The effect of cleaning treatment be by the silicon dangling bonds generate Si-OH, form the amino dielectric layer 130 of stable state, as Fig. 9 a~
9c.Then such as Figure 10 a~10c, first wafer 110 and the institute of the plasma-activated processing and cleaning treatment will be passed through
The second wafer 120 is stated to be bonded, due to atomic electronegativity O > N > Si > H, nitrogen-atoms electronegativity is greater than silicon atom, so that
2 electronics of N-Si singly-bound are formed closer to nitrogen-atoms, thus silicon atom band part positive charge (+), similarly oxygen atom band portion
Divide negative electrical charge (-), O-H key gradually weakens with Si-N key, and new keys N-H key and Si-O key increasingly generate, therefore reacts and generate NH3's
Speed can compare H2O is fast.Due to NH3The condition of supercriticality is 132.4 DEG C/11.28MPa, and object in a supercritical state
Matter is a kind of dense gaseous state, and density ratio general gas flow wants big two orders of magnitude, and close with liquid, viscosity is smaller than liquid,
But diffusion velocity is faster than liquid (about two orders of magnitude), so having preferable mobility and transfer performance.Therefore, described to make
NH3Reaction in a supercritical state, preferably when being bonded to first wafer 110 and second wafer 120
The range of temperature includes 132.4 DEG C~350 DEG C, and the range of reaction pressure includes 11.28MPa~20MPa, so as to reduce gas
Steep size.
As the further embodiment of the embodiment, in the mistake for being bonded first wafer 110 and second wafer 120
Cheng Zhong, in the H that the wafer bonding face 140 generates2The state of O includes one of supercriticality and gaseous state.
Specifically, due to the H2The supercriticality condition of O is 374.1 DEG C/22.06MPa, therefore to further decrease
The size of the bubble can also be by the technique during being bonded first wafer 110 and the second wafer 120
Condition control is in 374.1 DEG C/22.06MPa or more, in order to by the H2O is transformed into supercriticality, but this method need compared with
High reaction temperature and reaction pressure is unfavorable for the control of process conditions, therefore preferably lower to process conditions requirement, can
By the NH3It is changed into the scheme of supercriticality.
As the further embodiment of the embodiment, in the step for being bonded first wafer 110 and second wafer 120
In rapid, further include the steps that tempering.
Specifically, during being bonded first wafer 110 and the second wafer 120, it can also be only in the crystalline substance
The gaseous NH is formed at circle bonding face 1403, then the wafer after bonding is tempered, the tempering step
In process conditions be at least can be by the NH3It is changed into the NH of supercriticality3, or use can be by the gaseous H2O and institute
State NH3It is transformed into supercriticality, in order in the step of being tempered, achieve the purpose that reduce bubble size.
As the further embodiment of the embodiment, the area for the bubble that the wafer bonding face 140 is formed and institute
The ratio range for stating the area in wafer bonding face 140 includes 0.1%~1%.Thus under the premise of process conditions are relatively easy to control,
The size of the bubble at the wafer bonding face 140 is reduced, the quality of the wafer after improving bonding.
As the further embodiment of the embodiment, the wafer bonding method includes being applied to preparation SOI and back-illuminated type
One of CMOS, herein with no restriction.
In conclusion wafer bonding method of the present invention, carries out ammoniated treatment by the silicon oxide layer to wafer, to aoxidize
The surface of silicon layer forms amino dielectric layer, then by amino dielectric layer by wafer bonding, to form super face in wafer bonding face
The ammonia of boundary's state improves product quality to reduce bubble size under conditions of lower reaction temperature and reaction pressure
And yield.So the present invention effectively overcomes various shortcoming in the prior art and has high industrial utilization value.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology all without departing from the spirit and scope of the present invention, carries out modifications and changes to above-described embodiment.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should be covered by the claims of the present invention.