JP2581093Y2 - Semiconductor heat treatment equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor heat treatment apparatus used for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a chemical vapor deposition method (Chemi-Chemical Vapor Deposition) is used for forming an insulating film and forming a wiring metal.
The cal vapor deposition method is referred to as a CVD method for short. ) Is generally put to practical use. The crystal growth process of a compound semiconductor such as gallium arsenide (GaAs) includes metal-organic chemical vapor deposition (Metal-Org).
anic Chemical Vapor Depos
It is called an ition method, or MOCVD method for short. ) Has been put to practical use. There is a method of applying an arsenic pressure to the activation heat treatment after ion implantation of gallium arsenide (GaAs) or the like. In these methods, a reactive gas such as monosilane (SiH ₄ ), ammonia (NH ₃ ), and arsine (AsH ₃ ) is thermally decomposed to obtain a gas or a reaction product necessary for forming a semiconductor element. Here, a portion that thermally decomposes the reactive gas is referred to as a pyrolysis portion. A thermal decomposition part and a part for processing a semiconductor element which is an object to be processed for forming a semiconductor (hereinafter, referred to as a part to be processed)
It is called a processing unit. ) Are often in the same reactor.
At this time, the controllability of the processing unit temperature and the controllability of the thermal decomposition reaction are factors that influence the performance of the semiconductor device.

As a method of supplying a gas necessary for forming a semiconductor element, evaporation by heating a solid such as arsenic (As), indium (In), gallium (Ga), or indium arsenide (InAs) is sometimes used. Here, As (arsenic), In (indium), Ga (gallium), InA
Solids such as s (indium arsenide) are called solid sources,
A portion where the solid source is evaporated is called a thermal decomposition portion. Although the controllability of the temperature of the thermal decomposition section for evaporating the solid source also affects the performance of the semiconductor element, the thermal decomposition section and the processing section are often the same reactor.

Japanese Patent Application Laid-Open No. 3-12 / 1989 discloses an example in which a carrier gas heating section is independently provided before the gas is supplied to the processing section.
No. 5433 is disclosed. However, the purpose of this heating section is to preliminarily heat the carrier gas in order to reduce the temperature gradient in the processing section, and there is no description about the requirements for the thermal decomposition of the reactive gas and the evaporation of the solid source. Absent.

[0005]

As described above, the structure of the conventional heat treatment apparatus is composed of a thermal decomposition section for obtaining a gas used for forming a semiconductor element and a processing section for performing heat treatment of the object to be processed. However, there is a problem in that the respective temperatures cannot be controlled independently because they are integrated. The purpose of this invention is to separate the temperature control required for the thermal decomposition section to obtain the gas used for forming the semiconductor element and the temperature control required for the processing section for performing the heat treatment of the object to be processed for forming the semiconductor element. An object of the present invention is to provide a semiconductor heat treatment apparatus that can be performed at a low temperature.

It is an object of the present invention to provide a semiconductor heat treatment apparatus in which a communication part connecting a heat treatment part for forming a gas and a treatment part for forming a semiconductor element suppresses a temperature decrease of a gas flowing therethrough as much as possible.

[0007]

In order to achieve this object, the structure of the semiconductor heat treatment apparatus according to the present invention has the following features. A gas used for forming a semiconductor element is formed by thermal decomposition or heating of a solid source, and a heat treatment furnace capable of holding a heat treatment target at a processing temperature to form the semiconductor element. And a communicating section for communicating the thermal decomposition section, the thermal decomposition section, and the processing section for heat-treating the object to be processed. The communication portion has a gas flow path cross-sectional area and a gas flow length that can independently control the temperature of the thermal decomposition portion and the processing portion, and has a vacuum chamber around the outside of the communication portion. And

In implementing the present invention, it is preferable that a heat-resistant material is sealed in a vacuum chamber of the communication part. Further, in a preferred embodiment of the present invention, the semiconductor heat treatment apparatus is of a vertical type, the thermal decomposition section is installed above the processing section, and gas introduction to the thermal decomposition section is performed by the communication section below the thermal decomposition section. It is better to work through a vacuum chamber.

[0009]

According to the structure of the present invention, the thermal decomposition apparatus and the processing section are independent of each other in the semiconductor heat treatment apparatus, so that the temperature in each furnace can be controlled separately. A vacuum chamber is provided around the outer periphery of the connecting portion that connects the thermal decomposition section and the processing section, and the vacuum chamber is filled with a heat-resistant material as required. For this reason, as can be understood from the experimental data described later, since the temperature of the connecting portion is small, there is no precipitation at the connecting portion of the atomic gas formed in the thermal decomposition portion.

Further, in the structure of the vertical semiconductor heat treatment apparatus, since the gas supply pipe is attached to the lower part of the thermal decomposition part, heat radiation of the thermal decomposition part is less than that of the conventional structure in which the gas introduction part is attached to the upper part. In addition, the temperature of the thermal decomposition section can be controlled uniformly.

Further, according to the present invention, the communication portion has a double structure, which leads to an increase in strength resistance.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a semiconductor heat treatment apparatus according to an embodiment of the present invention; However, each drawing used in the description merely schematically shows the shape, size, and positional relationship of each component to the extent that these inventions can be understood. Note that, in this embodiment, other than the reaction gas supply control unit and the exhaust gas treatment device, devices for controlling gas, temperature, and pressure are not directly provided for the description of the present invention, so that illustration and description thereof are omitted. I have.

A condition required for such a semiconductor heat treatment apparatus in which the thermal decomposition section and the processing section are separated and independent is that a temperature drop is small in a portion from the thermal decomposition section to the processing section. The temperature of the pyrolysis section can be kept constant and the temperature distribution is uniform. That is, the temperature of the portion where the object to be processed is set in the processing section can be kept uniform and the distribution is uniform. The condition is an important factor that affects the controllability of thermal decomposition or evaporation of the solid source. Also,
In many cases, the reactor is made vertical to satisfy the conditions. Further, is a condition necessary to avoid that the atomic gas formed by thermal decomposition is precipitated as a solid due to a decrease in temperature, and in order to satisfy
A method is adopted in which the thermal decomposition section and the processing section are placed close to each other.

First Embodiment First, as a first embodiment, FIG. 1 shows a cross-sectional view of a semiconductor heat treatment apparatus. The apparatus for heat treating a semiconductor of the present invention has a thermal decomposition section 10 for thermally decomposing a gas used for forming a semiconductor element, a processing section 12, and a communication section (also referred to as a connection section) connecting the thermal decomposition section 10 and the processing section 12. .) 14
(FIG. 1). Further, the thermal decomposition unit 10 and the processing unit 1
2. The communicating part 14 is connected with a furnace tube, and the material of the furnace tube is, for example, quartz. Further, the thermal decomposition section 10 has an individual heater 16 on its outer periphery, while the processing section 12 has an individual heater 17 on its outer periphery.
The heaters 16 and 17 heat the pyrolysis section 10 and the processing section 12 independently.

Next, FIG. 2A is an enlarged sectional view showing only the connecting portion 14. As can be understood from FIG. 2A, the communication unit 14 includes the thermal decomposition unit 10 and the processing unit 12.
Are connected, and a gas passes through the inside of the thin tube 20. FIG. 2B is a sectional view taken along line II. The communication section 14 is a passage through which gas flows, and is designed so that temperature control in the thermal decomposition section 10 and temperature control in the processing section 12 can be performed independently. For example, the inner diameter of this capillary is 0.6 cm and the outer diameter is 1.
0 cm. The length L of the thin tube 20 is, for example, 20 cm.

Next, the slightly thick thick tube 21 covering the periphery of the thin tube 20 has, for example, an inner diameter of 3.6 cm and an outer diameter of 4.0 cm. Further, a vacuum chamber (also referred to as a vacuum sealing portion) 24 is provided between the thin tube 20 and the thick tube 21, and a heat insulating material such as a quartz wool material is provided in the vacuum chamber 24 as necessary. Fill. The volume of the thermal decomposition unit 10 is, for example, about 0.2 liter (6.4 cm in diameter, 6 c in height).
m) and about 10 liters (diameter 15c
m, height 57 cm). However, the above-described dimensions and volumes are merely examples, and do not specify the present invention at all. Other values may be used as long as the dimensions and volumes can achieve the present invention.

Next, the independence of the heat treatment unit 10 and the processing unit 12 will be described. FIG. 3 shows experimental data obtained by measuring the temperature of the thermal decomposition section and the temperature of the processing section. In the embodiment of the present invention, nitrogen gas is used as the gas, the gas flow rate is 1 liter / min, and the room temperature is 20 ° C.
The measured temperature in the furnace is determined by the thermal decomposition unit 10 and the processing unit 12.
The measurement is performed near the center of each room.
As the heater temperature, the temperatures of the pyrolysis section heater 16 and the processing section heater 17 are measured. As can be understood from FIG. 3, when the temperature of the thermal decomposition section 10 is raised from room temperature (20 ° C.) to 800 ° C., the temperature in the furnace tube of the processing section 12 is increased by 10 degrees (15.6 ° C. in actual measurement). However, if the target temperature of the processing unit 12 is set to 100 ° C. or higher, as can be understood from FIG. 3, the processing unit 1 is not affected by the temperature of the thermal decomposition unit 10 at all.
2. The temperature inside 2 can be controlled independently independently. 800 ° C for pyrolysis section
If the temperature of the heater 17 of the processing unit 12 is set to 96.0 ° C., the target temperature 1
00 ° C. can be achieved. On the other hand, if the target temperature is set to 800 ° C., the furnace tube temperature of the thermal decomposition section 10 can be maintained independently and independently without any influence even when the temperature of the processing section 12 is raised from room temperature to 800 ° C.

Next, a description will be given of a temperature drop at the connection portion, that is, the communication portion 14. According to this invention, the communicating part 14 connecting the thermal decomposition part 10 and the processing part 12 is excellent in heat resistance because quartz is used as a material, and the periphery of the narrow tube 20 through which the reactive gas flows is a vacuum chamber. Since it is 24, the thermal conductivity becomes extremely small. In addition, quartz wool (not shown) filled between the thin tube 20 and the thick tube 21 as required acts to prevent heat radiation of the communication portion 14 due to radiant heat. Further, when the inner diameter of the thin tube of the communicating portion 14 is sufficiently thin as 0.6 cm and nitrogen gas flows at 1 liter / minute, the gas flow rate is 59 cm / sec (1000 / 60πr).
^It is derived from Equation ² . ), And passes through a thin tube having a connection length of 20 cm in less than 0.4 seconds (calculated value is about 0.34 seconds). Therefore, the temperature drop in the communication portion 14 can be substantially ignored.

Next, the mechanical strength of the communication portion 14 will be described. Since the outer diameter of the thin tube 20 is changed from 1 cm to 4 cm, the mechanical strength is increased, and there is an advantage that the tube is hardly damaged when the furnace tube in the heat treatment apparatus is replaced or washed.

Second Embodiment Next, a description will be given of an embodiment of a vertical semiconductor heat treatment apparatus. FIG. 4 schematically shows a cross-sectional view of a semiconductor heat treatment apparatus for explaining the present invention. As can be understood from FIG. 4, the thermal decomposition section 10 is located above the processing section 12 for forming a semiconductor element, and the respective sections are connected by the communication section 14. And this communication part 1
4 is provided with a gas inlet. In the illustrated example, the gas inlet tube 18 passes through the space of the thin tube 20 of the communication portion 14,
It has a structure communicating with the thermal decomposition section 10. Further, the thermal decomposition section 10, the processing section 12, and the communication section 14 are connected by a furnace tube. The material of the furnace tube is, for example, quartz.
Next, the thermal decomposition unit 10 and the processing unit 12
6 and 17, so that the furnace temperature can be controlled independently. The gas flowing from the pipe 18 forming the gas inlet is supplied to the pyrolysis section 1.
After being heated to a high temperature and thermally decomposed therein, the gas reaches the processing section 12 through the narrow tube 20 of the communication section, and then the gas is exhausted from the lower portion of the processing section 12. At this time, since the gas introduction pipe 18 is connected to the lower part of the thermal decomposition part 10, the release of heat, which is more likely to escape from the upper part than in the conventional heat treatment furnace, can be suppressed. Further, according to the structure of the present invention, similarly to the case of the first embodiment, the gas introduction pipe 18 and the communication portion 14 are formed.
The thin tube 20 is covered with a thick tube 21, and the gas introduction tube 18, the thin tube 2
The space between the 0 and the thick tube 21 is vacuum-sealed so as to form a vacuum chamber 24. The vacuum chamber 24 is filled with a heat-resistant material as required. In such a vertical semiconductor heat treatment apparatus, as in the first embodiment, the thermal conductivity between the inside of the thin tube 20 and the outside of the thick tube 21 is small, and heat radiation due to heat radiation is small. Further, although the narrow tube 20 through which the high-temperature gas heated in the thermal decomposition section 10 flows and the gas introduction tube 18 are adjacent to each other, the space between the small tube 20 and the gas introduction tube 18 is in a vacuum, so that heat conduction is performed. Since the rate is small, the temperature drop in the communication section 14 can be suppressed. The above is the case of the semiconductor heat treatment apparatus using the reactive gas.
The same effect can be obtained in a heat treatment furnace of a type in which solid source such as arsenic (As) is evaporated at 0. In this case, since the solid source is filled into the pyrolysis section 10 through the gas introduction pipe 18, it is not necessary to remove the core tube from the apparatus for additional replenishment of the solid source. Further, similarly to the first embodiment, the thermal decomposition section 10 and the element processing section 12 have a double connection portion, so that the mechanical strength increases. In the above-described embodiment, the diameter of the thin tube is set to 0.6 cm. However, it is preferable to set an appropriate value within a range of about 0.3 cm to 2.0 cm. The pipe diameter may be arbitrarily determined depending on the design in relation to the gas flow length.

[0021]

As can be understood from the above description,
According to the structure of the apparatus for semiconductor heat treatment of the present invention, the furnace is constituted by a furnace tube provided with independent heaters for the pyrolysis section and the processing section, and the gas flow path from the furnace tube of the pyrolysis section to the furnace tube of the processing section. Is a sufficiently thin tube, so the furnace tube temperature can be controlled independently,
Therefore, the temperature controllability of each part is high. In addition, since the temperature of the gas flowing through the connecting portion is less reduced, there is no precipitation of the atomic gas formed in the thermal decomposition portion at the connecting portion.

Further, in the structure of the vertical type semiconductor heat treatment apparatus, the gas introduction pipe is attached to the lower part of the thermal decomposition part, so that the gas introduction part of the thermal decomposition part is larger than the conventional structure in which the gas introduction pipe is attached to the upper part. The heat radiation from the thermal decomposition part can be made more uniform. Also in this structure, the temperature of the gas flowing through the connection part does not decrease much. Further, since the communicating portion has a double structure, it can be expected that the mechanical strength is large.

If a semiconductor heat treatment apparatus having such a structure is applied to a CVD method or an MOCVD method, an apparatus effective for forming a good quality thin film and growing a good quality crystal can be provided.
In addition, when used for activation heat treatment after ion implantation of a semiconductor substrate, it is possible to stably supply an optimal arsenic pressure while maintaining a uniform temperature distribution of an object to be processed, and to provide an apparatus that realizes excellent activation heat treatment. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a semiconductor heat treatment apparatus according to the present invention.

FIG. 2A is an enlarged view for explaining a communicating portion of FIG. 1, and FIG. 2B is a cross-sectional view taken along line II of FIG.

FIG. 3 is data showing a temperature distribution in each furnace tube.

FIG. 4 is a cross-sectional view of a vertical semiconductor heat treatment apparatus according to the present invention.

[Explanation of symbols]

 10: Thermal decomposition section 12: Processing section 14: Communication section (connection section) 16: Heater of thermal decomposition section 17: Heater of processing section 18: Gas introduction pipe 19: Gas exhaust pipe 20: Thin pipe 21: Thick pipe 22: Gas Channel 24: vacuum chamber

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/205 C23C 16/46 C23C 16/52 H01L 21/203 H01L 21/324

Claims (4)

(57) [Scope of request for utility model registration] An apparatus for heat treating a semiconductor, wherein a gas used for forming a semiconductor element is formed by thermal decomposition of a reactive gas or heating of a solid, and a heat treatment target can be maintained at a processing temperature in order to form the semiconductor element. In the apparatus for heat treatment, the apparatus for heat treatment includes a thermal decomposition section for obtaining the gas, a processing section for heat-treating the object to be processed, and a communication section for communicating the thermal decomposition section and the processing section. Has a flow path cross-sectional area and a flow path length of the gas that can independently control the temperature of the thermal decomposition section and the processing section, and has a vacuum chamber around the outside of the communication section. For semiconductor heat treatment. 2. An apparatus for heat treating a semiconductor, wherein a heat-resistant material is sealed in the vacuum chamber according to claim 1. 3. The apparatus for heat treating a semiconductor according to claim 1, wherein said apparatus is a vertical type, said thermal decomposition section is installed above said processing section, and gas is introduced into said thermal decomposition section from below said thermal decomposition section. An apparatus for heat-treating a semiconductor, comprising an introduction pipe, wherein a vacuum chamber is provided around a portion of the introduction pipe adjacent to the thermal decomposition section and around the communication section. 4. A semiconductor heat treatment apparatus, wherein a heat-resistant material is sealed in the vacuum chamber according to claim 3.