JP2007115926A - Thermal head and heat treatment equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal head and heat treatment equipment arranged such that a heat treatment article can be heat treated instantaneously while reducing energy consumption. <P>SOLUTION: In a holding structure 3, a light absorbing/heat generating body 4 composed of carbon and generating heat by absorbing light energy is arranged in contact with a heat treatment article 1 or on the side opposite to the heat treatment article 1. The light absorbing/heat generating body 4 is irradiated with light and the temperature is raised instantaneously. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal head and a heat treatment apparatus suitable for applying heat treatment to an object to be heat treated, for example, heat treatment in a semiconductor, a semiconductor device or the like.

  In the manufacture of semiconductor devices such as various single semiconductor elements such as bipolar transistors, insulated gate field effect transistors (MOS transistors), and semiconductor integrated circuits, for example, repair of crystal defects in semiconductors, activation of introduced impurities, amorphous Many heat treatments, so-called annealing treatments, are performed in crystallization from a crystalline semiconductor thin film.

In particular, a thin film crystallization technique is important for a thin film transistor formed on an insulator or an insulating film layer.
As a conventional thin film crystallization technique, a method of heating at a high temperature of 1000 ° C. to 600 ° C. for 2 hours to 20 hours using an electric furnace is known (for example, see Patent Document 1).
Alternatively, a laser annealing technique is known in which, for example, a semiconductor thin film is melted for a short time and solidified and crystallized using a pulse laser.
Japanese Patent Laid-Open No. 2001-210631

However, the method using an electric furnace has a problem that it takes a long time to stabilize at a required temperature and the workability is poor.
In addition, in the case of laser annealing, there is a restriction that the target heat-treated body material needs to be a material that exhibits high absorbability with respect to the wavelength light of the annealing laser light. There are limitations. Alternatively, there is a restriction that the wavelength of the laser to be used is restricted and a high-power laser or the like cannot be used.

  The present invention enables a required heat treatment for various heat-treated materials such as a semiconductor or a semiconductor device, such as an instantaneous heat treatment, and can reduce energy consumption with a simple configuration. A thermal head and a heat treatment apparatus are provided.

  The thermal head according to the present invention comprises a holding structure, and a light absorption heating element made of carbon that generates heat upon absorption of light energy, disposed on the side facing or facing the heat-treated body. An optical means for irradiating irradiation light for supplying the light energy is provided.

  As described above, in the thermal head according to the present invention, the light-absorbing heating element made of carbon is heated by light irradiation, and the target heat-treated body is thereby heat-treated, which constitutes the light-absorbing heating element. Since carbon has high heat resistance and a wide absorption wavelength range, it has a high degree of freedom in wavelength of irradiation light and can be heated at high temperatures.

Further, the present invention is the above-described thermal head according to the present invention, wherein the irradiation light optical means emits the irradiation light from the light source unit to the contact or opposite side of the light-absorbing heating element with the heat-treated body. And an optical system that leads to the light absorption heating element from the opposite side.
Further, the present invention is the above-described thermal head according to the present invention, wherein the optical means of the irradiation light has a light source part, and the light source part is directly connected to the light absorption heating element. And
Further, the present invention is the above-described thermal head according to the present invention, wherein the light absorption heating element is formed on a transparent substrate having high heat resistance and held by the holding structure.

  Further, the present invention is the above-described thermal head according to the present invention, wherein the light absorption heating element is heated in pulses, and the pulsed heating is performed by supplying light energy to the light absorption heating elements by pulse light irradiation. Or a light irradiation position on the light absorption heating element is moved intermittently or a combination thereof.

Further, the present invention is the above-described thermal head according to the present invention, wherein the light irradiation time length of the pulsed light irradiation is selected from 0.1 μs to 10 s.
Further, the present invention is the above-described thermal head according to the present invention, wherein the wavelength of the irradiation light with respect to the light absorption heating element is 0.2 μm to 1.5 μm.
Further, the present invention is the above-described thermal head according to the present invention, wherein a heat-resistant and oxidation-resistant protective film is coated on the surface of the light-absorbing heating element that contacts or faces the heat-treated body. It is characterized by.

The thermal head has a thermal head and a thermal head, and the thermal head is arranged such that a light absorption heating element made of carbon that generates heat by absorbing light energy is in contact with or opposite to the thermal process object. It consists of
An optical means for irradiating the light absorption heating element with irradiation light for supplying the light energy is provided.

Further, the heat treatment apparatus according to the present invention is the above-described heat treatment apparatus, wherein the arrangement portion of the object to be heat-treated and the thermal head have at least a moving mechanism that moves relatively in the state of facing or facing each other. It is characterized by having either one.
Further, the present invention is the above-described heat treatment apparatus, wherein the contact or facing area of the light absorption heating element with the heat treatment body is selected larger than the heat treatment region of the heat treatment body, and the light energy The light irradiating position for providing the light is configured to move with respect to the light absorption heating element.

  In the present invention, the carbon constituting the light-absorbing heating element can be composed of pure carbon, but it may be carbon having a trace amount of contaminants such as hydrogen mixed during the production of the film. It is.

As described above, according to the thermal head of the present invention, the light-absorbing heating element made of carbon is heated by light irradiation, thereby heat-treating the target heat-treated body. However, carbon has a heat resistance of 2000. It has excellent heat resistance of from 5,000 to 5,000 ° C., and has a light absorptivity with respect to a wavelength of 0.2 μm to 1.5 μm ranging from ultraviolet to infrared.
Therefore, a target heat-treated body in which the target heat-treated body material in the case where laser annealing is directly performed on the heat-treated body is required to be a material having high absorbability with respect to the wavelength of the annealing laser beam. Material constraints and laser wavelength limitations are greatly improved. This makes it possible to use a laser that can obtain high output or high energy, and can stably and instantaneously heat the light-absorbing heating element, and hence stable and instantaneously heat the object to be heat-treated. And an energy saving effect can be obtained.

  Further, since the heat treatment apparatus according to the present invention is performed by a thermal head separate from the heat-treated body, the light-absorbing heat-generating body is covered with the heat-absorbing heat-generating body as in the case where the light-absorbing heat-generating body is attached to the heat-treated body. Adhering to the heat-treated body and further removing it after the heat treatment avoids the labor and the risk of damage and fouling in the heat-treated body.

Hereinafter, embodiments of a thermal head and a heat treatment apparatus according to the present invention will be described by way of example. However, the present invention is not limited to this.
FIG. 1 is a schematic sectional view of an embodiment of a heat treatment apparatus according to the present invention having a thermal head according to the present invention.
This heat treatment apparatus includes an arrangement portion 100 for the heat-treated body 1 and a thermal head 2.

The thermal head 2 is configured such that a light-absorbing heating element 4 made of carbon that generates heat by absorbing light energy is arranged on a holding structure 3 such as a housing on the side facing or facing the heat-treated body 1. Further, an optical means 6 for irradiating irradiation light 5 for supplying light energy to the light absorption heating element 4 is provided. This optical means 6 has an optical system such as a condensing lens for guiding the irradiation light 5 to the light absorption heating element 4 from the opposite side of the light absorption heating element 4 facing or facing the heat-treated body 1. The optical system is disposed and held in the holding structure 3.
In the example of FIG. 1, the irradiation light optical means 6 includes a light source unit 7 of the irradiation light 5, for example, a laser light source, and the light source unit 7 is disposed and held in the holding structure 3.
The light absorption heating element 4 is disposed on a transparent substrate 9 having high heat resistance and high transmittance with respect to irradiation light held by the holding structure 3.

The arrangement portion 100 of the heat-treated body 1 and the thermal head 2 have at least a moving mechanism that relatively moves the light absorption heating element 4 of the thermal head 2 in contact with or facing the heat-treated body 1. Have either one.
In FIG. 1, as indicated by an arrow on the base 10, on a moving stage 11 configured to move in one direction along the heat-treated body 1 or in a direction indicated by the arrow and in two directions orthogonal thereto. Be placed.

In this configuration, irradiation light 5 from the light source unit 7, for example, laser light, for example, excimer laser light, is irradiated to the light absorption heating element 4 made of carbon through an optical system. Since this light absorption heating element 4 has a high light absorptivity with respect to this laser light, this irradiation light 5 is efficiently absorbed by the light absorption heating element 4 and its light energy is converted into heat, and light absorption heat generation. The body 4 generates heat instantaneously.
And this heat is given to the light absorption heat generating body 4, and this is heat-processed. The heat treatment position is scanned by the movement of the thermal head 2 by the moving stage 11, and for example, the entire area of the heat treatment object 1 can be heated. Along with this movement, the laser beam is turned on and off to be limited to a predetermined portion. Heat treatment can also be performed. In this case, as described above, the light-absorbing heating element 4 is instantaneously heated, so that a predetermined part of the heat-treated body can be accurately heated in a limited manner.

FIG. 2 is a schematic sectional view of another embodiment of the present invention. In the embodiment shown in FIG. 1, the thermal head 2 is moved. However, as shown in FIG. 2, the thermal head 2 is held in a fixed state, and the heat-treated body 1 is placed on the moving stage 11. It can also be set as the arrangement.
In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals and redundant description is omitted. In this example, for example, the light source unit 7 is a laser light source and its spot is small. In this case, laser light, that is, irradiation light is directly introduced into the transparent substrate 9 that holds the light absorption heating element 4. In this case, the distance between the light absorption heating element 4 and the laser emission end is preferably 100 μm to 1 cm. However, by using a light guide such as an optical fiber, it is possible to make the length spatially acceptable, for example, 10 cm.

FIG. 3 is a schematic cross-sectional view of the main part of still another embodiment of the present invention.
1 and 2, the light source unit 7 such as a laser light source is disposed in the holding structure 3 of the thermal head 2. However, as shown in FIG. Although not shown in the figure, for example, in the optical system 8 in the holding structure 3, the irradiation light can be introduced using a light guide such as an optical fiber.

FIG. 4 is a schematic sectional view of still another embodiment of the present invention. 4, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals and redundant description is omitted. In this embodiment, the light-absorbing heating element 4 is in contact with or opposed to the heat-treated body 1. This is a case where the area is selected to be equal to or larger than the area to be heat-treated of the body 1 to be heat-treated.
And as a structure which moves the light source part 7 with the movement stage 11, the heating part moves as a structure which the irradiation light spot, ie, the light irradiation position which gives light energy, moves intermittently with respect to the light absorption heat generating body 4. This is the case. This is a case where the heating position with respect to the object to be heat-treated 1 is moved, and the pulsed irradiation is substantially performed.

In the above-described configuration, the light absorption heating element 4 is heated in a pulse manner. This pulsed heating is performed by supplying light energy to the light absorption heating element 4 by pulse light irradiation, moving the light irradiation position on the light absorption heating element 4 intermittently, for example, or a combination thereof.
The light irradiation time length of this pulsed light irradiation is preferably a short time in terms of energy saving. In the light-absorbing heating element 4, for example, a normal heat treatment temperature, for example, a heat treatment temperature of 600 ° C. to 1200 ° C. for a semiconductor is used. For the heating necessary to obtain the temperature, the light irradiation time length is selected from 0.1 μs to 10 s.
Moreover, the wavelength of the irradiation light with respect to the light absorption heat generating body 4 can be selected in the range of 0.2 micrometer-1.5 micrometers of the wavelength which the light absorption heat generating body 4 by this carbon has a high absorption factor.

The light absorption heating element 4 can be formed on a transparent substrate such as glass or quartz by, for example, a plasma CVD (chemical vapor deposition) method, a plasma sputtering method, an ionization vapor deposition method, or the like.
In the plasma CVD method, for example, methane CH ₄ and acetylene C ₂ H ₂ are used as a raw material gas to decompose the gas by plasma discharge. In this example, the light-absorbing heating element is mainly composed of carbon but is a compound containing a trace amount of hydrogen. 4 is formed on the transparent substrate 9.
In the plasma sputtering method, for example, a carbon target is used, for example, argon, hydrogen, or a mixed gas thereof is used to generate high-energy ions by plasma discharge, and the ions collide with the target to cause carbon to pass through the transparent substrate 9. The light-absorbing heating element 4 made of carbon can be formed by sputtering on the surface.

In the ionized vapor deposition method, for example, CH ₄ or C ₂ H ₂ is used, and this gas is heated and decomposed and ionized by, for example, energizing a heating filament to generate CH ions, CH ₂ ions, and CH ₃ ions. A magnetic field is applied to increase the ionization efficiency. And the light absorption heat generating body 4 is formed by ionization vapor deposition in the state which applied the required electric potential to the holding body holding the transparent substrate 9. In this case, the carbon contains a small amount of hydrogen.

The thickness of the light absorption heating element 4 made of carbon is desirably 0.1 μm to 200 μm, which is a thickness for heating the heating element to a sufficiently high temperature within the heating time.
Then, as shown in FIG. 5A, the light absorption heating element 4 can be formed on the transparent substrate 9 as described above, but it is formed thick enough to maintain the mechanical strength itself. In this case, as shown in the cross-sectional view of FIG. 5B, the transparent substrate 9 is not provided, and the light absorption heating element 4 itself can carry the structure.

The distance between the light-absorbing heating element 4 and the heat-treated body 1 of the thermal head 2 is about 500 μm or less and as close as possible so that the heat generated by the light-absorbing heating element 4 is effectively given to the heat-treated body 1 by conduction or radiation. It is desirable to perform the intended heat treatment.
The distance between the light absorption heating element 4 and the heat-treated body 1 can be automatically controlled by providing a mechanism for measuring the distance.

Although not shown, the surface of the light-absorbing heating element 4 that is in contact with or opposite to the heat-treated body 1 may be coated with a heat-resistant and oxidation-resistant protective film to improve the durability of the light-absorbing heating element 4. it can. This protective film can be formed of, for example, SiO ₂ , SiN, AlN, SiC, TiN, Mo, W, Ta, or the like.

  The thermal head and heat treatment apparatus according to the present invention can be applied to various heat treatments. For example, in the semiconductor field, an object to be heat-treated is a semiconductor layer formed on a semiconductor substrate or an insulating substrate, for example, an activation heat treatment having p-type impurities and n-type impurities introduced by ion implantation or the like, or amorphous. It can be applied to crystallization heat treatment of a crystalline semiconductor, improvement of interface state, heat treatment such as defect repair.

  As described above, in the present invention, since the heat treatment for the object to be heat treated is performed by a thermal head separate from the object to be heat treated, the size, material, and heat treatment conditions of the object to be heat treated are determined. The constraints are greatly improved. In particular, because the heating part is a light-absorbing heating element made of carbon, the absorption wavelength range is wide as described above, so it is possible to use a light source that can obtain large energy and power, enabling instantaneous heating, and efficient operation. In addition, stable heat treatment can be performed. Thereby, the energy saving effect can be enhanced.

  In addition, since the thermal head is separated from the heat-treated body, the light-absorbing heat-generating body is attached to the heat-treated body, as in the case where the light-absorbing heat-generating body is attached to the heat-treated body, Furthermore, by removing this after the heat treatment, there are many advantages such as labor and avoidance of damage, fouling and the like in the object to be heat treated.

It is a schematic sectional drawing of an example of the heat processing apparatus by this invention which has the thermal head by this invention. It is a schematic sectional drawing of an example of the heat processing apparatus by this invention which has the thermal head by this invention. It is a schematic sectional drawing of the principal part of an example of the heat processing apparatus by this invention which has the thermal head by this invention. It is a schematic sectional drawing of an example of the heat processing apparatus by this invention which has the thermal head by this invention. A and B are schematic sectional views of the light-absorbing heating element of the device of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat-treated body, 2 ... Thermal head, 3 ... Holding structure, 4 ... Light absorption heating element, 5 ... Irradiation light, 6 ... Optical means, 7 ... Light source part, 8 ... Optical system , 9 ... Transparent substrate, 10 ... Base, 11 ... Stage

Claims (11)

In the holding structure, a light absorption heating element made of carbon that generates heat by absorption of light energy is arranged on the side facing or facing the heat-treated body, and
A thermal head comprising optical means for irradiating the light absorption heating element with irradiation light for supplying the light energy. The optical means for the irradiation light has an optical system for guiding the irradiation light from the light source unit to the light absorption heating element from a side opposite to the side where the light absorption heating element is in contact with or opposite to the heat-treated body. The thermal head according to claim 1. The optical means of the irradiation light has a light source part,
The thermal head according to claim 1, wherein the light source unit is directly connected to the light absorption heating element. The thermal head according to claim 1, wherein the light absorption heating element is formed on a transparent substrate having high heat resistance and held by the holding structure. The light absorption heating element is heated in pulses,
The pulsed heating is performed by supplying light energy to the light-absorbing heating element by pulsed light irradiation, moving the light irradiation position on the light-absorbing heating element intermittently, or a combination thereof. The thermal head according to claim 1. 2. The thermal head according to claim 1, wherein a light irradiation time length of the pulsed light irradiation is selected from 0.1 [mu] s to 10 seconds. 2. The thermal head according to claim 1, wherein a wavelength of irradiation light with respect to the light absorption heating element is 0.2 μm to 1.5 μm. 2. The thermal head according to claim 1, wherein a heat-resistant and oxidation-resistant protective film is coated on a surface of the light-absorbing heat generating member facing or facing the heat-treated body. It has an arrangement part of a body to be heat-treated and a thermal head,
The thermal head is configured such that a light-absorbing heating element made of carbon that generates heat by absorbing light energy is disposed so as to contact or face the heat-treated body,
A heat treatment apparatus comprising optical means for irradiating the light absorption heating element with irradiation light for supplying the light energy. 10. The heat treatment according to claim 9, wherein the arrangement portion of the object to be heat-treated and the thermal head have a moving mechanism that relatively moves in a state of being in contact with or facing each other. apparatus. The contact or facing area of the light-absorbing heat generating body with the heat-treated body is selected to be larger than the heat-treated region of the heat-treated body, and the light irradiation position for applying the light energy is relative to the light-absorbing heat-generating body. The heat treatment apparatus according to claim 9, wherein the heat treatment apparatus is configured to move.

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