JPS6020508A - Heating apparatus - Google Patents

Abstract

PURPOSE:To heat and treat only a material to be heated and treated or only a necessary section on the material to be heated and treated uniformly and efficiently with high accuracy by heating the desired section of the material to be treated when the whole of the material to be heated and treated is heated. CONSTITUTION:When a semiconductor wafer 2 as a material to be heated and treated is set on a stage 4, an inert gas 5 is fed from a gas supply section 6. The stage 4 is turned by a motor 21 at the same time. The semiconductor wafer 2 under the state of revolution is heated by microwaves 8, which are generated by a microwave generating section 9 and guided and projected into a treating chamber 1 from a waveguide 10. Laser lights oscillated from a laser oscillating section 13 are projected partially to the semiconductor wafer 2 as spotty laser lights 12 from a laser projecting section 15, and focussed partially to heat the wafer, thus forming a high-temperature region 16. The laser projecting section 15 is formed in structure in which it scans in the radial direction of the semiconductor wafer 2, and the wafer can be heated uniformly when the speed of travel of the laser projecting section 15 is adjusted in succession at that time and laser- light projecting time in each section of the semiconductor wafer 2 is made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat treatment technique, and relates to a technique effective for use in, for example, heat treatment of semiconductor wafers in the manufacture of semiconductor devices and heat treatment accompanied by reactions.

[Background technology]

As is well known, when manufacturing semiconductor devices, there are various processes such as crystal growth treatment, impurity diffusion treatment, crystal annealing treatment,
Passivation film generation treatment, dry etching treatment,
Heat treatment or heat treatment accompanied by reaction is performed in various forms such as photoresist bake treatment.

Conventionally, these heat treatment methods were developed, for example, in 1968.
As described on page 106 of Electronic Materials published on February 1st, various heating methods such as heaters and high frequency heating have been devised. In these heat treatment methods, the object to be heated is supported in a heating atmosphere with a jig or the like and heated, or the object to be heated is directly grounded to a heating source such as a heater block. In either method, the object to be heated is in contact with the support.

In order to accurately heat the object to be heated in the above method, a jig for supporting the object to be heated other than the object to be heated is required.

Heater blocks and the like must be heated with high precision, just like the heat-treated objects. At the same time, the surrounding walls of the processing chamber are also heated. For this reason, the heating efficiency of the above-mentioned method is extremely poor. ! l'! It's a long time. However, if the jig or heater block is thick, there is a drawback that the device becomes larger.

In addition, in heat treatment that involves a reaction, parts other than the object to be heated that do not require reaction are heated, so reactions occur in areas other than the object to be heated that do not require reaction, and unnecessary products are generated.
It is generated on the support jig for the object to be heated and on the inner wall of the processing chamber. As a result, due to the heat treatment accompanied by a reaction, when manufacturing semiconductor elements, it falls onto the object to be heated for manufacturing semiconductor elements.
This leads to a decline in the quality of manufactured semiconductor devices. Furthermore, in this case, incidental work such as cleaning work of unnecessary products generated on the walls of the processing chamber increases.

Furthermore, since the above-mentioned method has an overall heating structure, it is difficult to selectively heat the object to be heated externally.

[Purpose of the invention]

The purpose of the present invention is to provide a heat treatment technique for accurately, uniformly and efficiently heating only the entire part of the object to be heated, or only the required portion of the object to be heated, and to provide an object to be heated that requires reaction with a reactant. The purpose of the present invention is to provide a reaction treatment technology that activates only a region and causes it to react.

The above and other objects and novel features of the present invention include:
It will become clear from the description herein and the accompanying drawings.

[Overview of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, the semiconductor wafer is heated by irradiating the entire rotating semiconductor wafer with microwaves to heat the entire semiconductor wafer, and by irradiating the semiconductor wafer with laser light while moving in the radial direction of the semiconductor wafer to locally heat the semiconductor wafer. Highly accurate and efficient annealing processing can be achieved by raising the temperature locally and in a short time to a high temperature.

[Embodiment 1] FIG. 1 is a sectional view showing the main parts of a heat treatment apparatus according to an embodiment of the present invention, and is a sectional view of the main parts showing an example of application to an annealing apparatus for semiconductor wafers in the manufacture of semiconductor devices. be. That is, when a semiconductor wafer is subjected to ion implantation, it is necessary to perform annealing to recover crystal damage caused to the surface layer of the semiconductor wafer due to the ion implantation.

In the figure, the processing chamber 1 is a box made of a material (conductive and low electrical resistance, e.g. metal) that reflects microscopic radiation, and heats the semiconductor wafer 2 that is the object to be heated. It is a room. In the center of the processing chamber 1, a stage 4 for holding a semiconductor wafer 2 (with crystal damage 3 on the surface) in a bottle is provided. This stage 4 is made of a material that allows microwaves to pass through and has low electromagnetic loss, such as quartz.

Further, a cleaned inert gas 5 is supplied into the processing chamber l from a gas supply section 6 through a gas supply pipe 7. On the other hand, microwaves 8 are generated by a microwave generator 9 and irradiated into the processing chamber 1 through the entire waveguide 10, thereby heating the semiconductor wafer 2.

At the same time, laser light 12 is generated from the laser oscillation unit 13 through the upper window 11 of the processing chamber 1, and is irradiated onto the semiconductor wafer 2 from the laser irradiation unit 15 installed in the station unit 14.
The irradiated area is additionally heated and becomes a high temperature region 16.

On the other hand, the temperature of this high temperature area 16 is measured by a temperature sensor 17 installed in the same station section 14.

Information measured by the temperature sensor 17 is sent to the temperature measurement unit 1
8 and transmitted to the overall control section 19. On the other hand, the stage 4 is rotated by a motor 21.

In the overall control section 19, the intensity of the microwave 8 generated from the microwave generation section 9 and the laser beam 120 generated from the laser oscillation section 13 are determined according to the specification of the amount of gas supplied from the gas supply section 6 and the temperature measurement section 18. It has a function of controlling the strength and keeping the temperature of the high temperature region 16 on the semiconductor sea urchin 2 constant.

At the same time, the overall control section 19 operates the station drive section 20 that moves the station section 14 left and right, thereby controlling the required speed and amount of movement of the station section 14. Also, the motor 21 is operated to rotate the semiconductor wafer 2 at a required speed.Meanwhile, the inert gas 5 is supplied into the processing chamber 1.
A clean inert atmosphere is created inside, and at the same time, the exhaust gas 23 is exhausted from the exhaust section 22.

Next, a method of annealing crystal damage generated on the surface of the semiconductor wafer 2 using the above-mentioned apparatus will be explained.

When the semiconductor wafer 2, which is the object to be heated, is set on the stage 4, an inert gas 5 is supplied from the gas supply section 6. At the same time, the stage 4 is rotated by the motor 21. The semiconductor wafer 2 in a rotating state is heated by the microwave 8 generated by the microwave generator 9 and guided into the processing chamber 1 from the waveguide 10. In this heating, only the semiconductor wafer 2 is heated because each part other than the semiconductor wafer 2 is made of a material with low electromagnetic loss.

Further, the laser beam oscillated from the laser oscillation unit 13 is outputted from the laser irradiation unit 15 as a spot-shaped laser beam 12,
The semiconductor wafer 2 is partially irradiated and heated locally to create a high temperature region 16. The crystal damage 3 formed on the surface layer of the semiconductor wafer 2 is caused by this high temperature region 16.
cyannealed. Further, the laser irradiation section 1
5 has a structure that scans in the radial direction of the semiconductor wafer 2, and by moving the high temperature region 16, it is possible to perform crystal annealing on the entire surface of the semiconductor wafer 2. At this time, uniform heating can be achieved by sequentially adjusting the moving speed of the laser irradiation section 15 and making the laser beam irradiation time constant for each part of the semiconductor wafer 2.

Further, the overall control section 19 controls the intensity of the microwave 8 irradiated from the microwave generation section 9, the intensity of the laser beam 12 oscillated from the laser oscillation section 13, according to the wafer temperature information from the lf measurement section 18, By controlling the supply amount of the inert gas 5 supplied from the gas supply section 6, etc., the high temperature region 16 can be controlled with high precision, and high-quality annealing processing can be performed.

[Embodiment 2] FIG. 2 is a cross-sectional view of essential parts showing an example of the present invention in which a retention film is generated on the surface of a semiconductor wafer in manufacturing a semiconductor device.

This device has a processing chamber 24 made of a material that reflects microwaves as in Example 1, and a reaction chamber in the center made of a material that can pass microwaves and withstand reactants. In the reaction chamber 25, a semiconductor wafer 26, which is an object to be processed, is held on a stage 27 made of a material that transmits microwaves.

On the other hand, a reaction gas 2 is supplied into the reaction chamber 25 from a gas supply section 28.
9 is supplied, and after the reaction treatment is exhausted from the exhaust section 30 as exhaust gas 38. On the other hand, in the processing chamber 24, a microwave 33 is transmitted from a microwave supply section 31 through a waveguide 32.
is supplied.

The microwave 33 is also transmitted into the reaction chamber 25 .

On the other hand, outside the reaction chamber 25, there is a pair of magnets 34 that can move left and right, front and back, and a strong magnetic field 35 acts on the semiconductor wafer 26.

When the microwave 33 and the reaction gas 29 are supplied to the area where the strong magnetic field 35 is acting, the electrons of the microwave 33 undergo spin motion due to the strong magnetic field, and the reaction gas 29 is excited.
It is activated and becomes ready to react.

The overall control unit 36 controls the supply amount and supply timing of the reaction gas 29 supplied from the gas supply unit 28, and at the same time controls the microwave 3 supplied from the microwave supply unit 31.
30 strength and simultaneously control the position of the magnet pair 34.

Next, a method for forming the protective film 37 on the surface of the semiconductor wafer 26 using the above-mentioned apparatus will be explained.

A semiconductor wafer 26, which is an object to be processed, is set on a stage 27. When the semiconductor wafer 26 is set on the stage, the microwave 33 is irradiated into the processing chamber 24 from the microwave supply section 31 via the waveguide 32, and the reaction chamber 25 is irradiated with the microwave 33.
It is also transmitted transparently.

As a result, only the semiconductor wafer 26 is heated.

On the other hand, a reaction gas 29 is supplied into the reaction chamber 25 from the gas supply section 28, is activated by the microwave 33 and the strong magnetic field 35 in the region of the strong magnetic field 35, reacts on the semiconductor wafer 26, and becomes a reactant product. A certain protective film 37 is formed.

The inner wall of the reaction chamber 25 and the surface of the stage 27 are extremely low in temperature compared to the surface of the semiconductor wafer 26 due to microwave transmission, and are inert to the reaction gas 29,
No reaction occurs with the reaction gas 29, and no unnecessary products are generated. This allows the reaction of only the semiconductor wafer 26 to be carried out with high precision and high quality.

〔effect〕

(1) The present invention uses a heating source because of the effect that the heating energy of the object to be heated or the capacity of the reaction energy of the reaction object can be minimized because only the object to be treated and the reactant are subjected to direct heat treatment or reaction treatment.

The output of the reaction energy source can be minimized.

(2) Since the object to be heated is self-heated by electromagnetic waves such as microwaves without coming into direct contact with a heater block, etc., the contact area with the holding stage can be reduced, and heat can escape from the object to be heated. Therefore, uniform heating of the object to be heated can be maintained, and highly accurate heating is possible.

(3) As mentioned in (2) above, since it is difficult for heat to escape from the object to be heated, extra heating becomes unnecessary, and the output of the heating source can be reduced.

(4) As mentioned in (1) and (2) above, since the reduction in the capacity of the object to be heated and the heat radiation from the object can be reduced, the heating capacity is reduced, so the object to be processed can be efficiently heated in a short time. can do.

(5) The object to be processed is heated by electromagnetic waves such as microwaves. This heating generates heat due to electromagnetic losses such as resistance loss and dielectric loss that occur within the workpiece due to electromagnetic wave irradiation.
Heating efficiency is extremely high due to heat generation inside the processed object. Furthermore, heating efficiency is further improved because only the necessary portions are heated intensively using laser light or the like.

(6) When processing the object to be processed using a reactive substance, place only the region that requires the reaction in a strong magnetic field, supply the reactant and microwave, and only apply the reaction substance and the area of the object that requires the reaction. Activate and react. For this reason,
Unlike conventional methods, unnecessary products are less likely to be generated, and the inner walls of the processing chamber and the surface of the object to be heated are less likely to be contaminated with unnecessary products.

(7) Example 1 above. In the second embodiment, since the objects to be processed are processed one by one, the device structure can be simplified and downsized, and automatic processing and continuous processing are also possible.

(8) Since the above (21(5) and (6)) allow uniform and highly accurate heating or reaction treatment without contamination, a synergistic effect is achieved that enables highly reliable heat treatment with stable quality.

(9) Since the object to be processed is always heated at a relatively high temperature by microwaves, a high temperature region can be created in a relatively short time by laser beam irradiation, and the time required for annealing etc. can be shortened.

Although the invention made by the present inventor has been specifically explained based on examples, the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist of the invention. Needless to say.

For example, in addition to the method of applying a strong magnetic field to this example, it is also possible to activate a reaction phenomenon by irradiating microwaves while acting as a rotating magnetic field.

In this case, the improvement in reaction efficiency has the additional effect of enabling high-quality reaction and shortening of processing time.

Further, the present invention can be carried out in a high pressure atmosphere or in a normal pressure atmosphere.

The above-mentioned treatment can be performed in a low-pressure atmosphere, in a vacuum, and in a substance that transmits microwaves, and in any case, the same effects as in the above embodiment can be obtained.

[Application field]

In the above explanation, the invention made by the present inventor will be mainly applied to the application field for which the invention is based, which is the annealing treatment for crystal damage on the surface of a semiconductor wafer in the manufacture of semiconductor devices, and the formation of a protective film on the surface of the semiconductor wafer. Although the case where the application is explained is not limited to this, for example, for semiconductor materials and all substances that have a low electromagnetic loss effect, crystal growth methods, vapor phase growth methods, impurity diffusion treatment methods, It can be applied to various heat treatment methods and heat treatments involving reactions, such as a crystal annealing treatment method, a dry etching method, a development treatment method, and a photoresist dry removal treatment method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a suction part of a heat treatment apparatus according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part of a reaction treatment apparatus according to a second embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. A heating device that includes a heating mechanism that heats the entire object to be processed and a high-temperature heating mechanism that heats a desired portion of the object. 2. Patent claim @Claim No. 1 characterized by having a heating mechanism that irradiates the entire object to be treated with microwaves, and a high-temperature heating mechanism that irradiates a desired part of the object to be treated with laser light.
Heating device as described in section. 3. The support base that supports the object to be processed is rotatable and can be heated at high temperatures! 3. The heating device according to claim 2, wherein the heating device is configured to change the laser beam irradiation position over time. 4. Claims that include a heating mechanism that irradiates the entire object to be processed with microwaves, and a high-temperature heating mechanism that partially heats the object by applying a strong magnetic field to a space surrounding a part of the object. The heating device according to item 1. 5. The heating device according to claim 4, wherein the strong magnetic field region can be controlled in variation. 6. The heating device according to claim 4, wherein a reactant is present in the space.