JPS62500695A - Technology for growth of epitaxial compound semiconductor films - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Technique for Growth of Epitaxial Compound Semiconductor Films This invention is directed to the growth of Group 1-V semiconductors. This invention relates to a method for growing an epitaxial shell film containing a compound. More specifically, this invention Organometallic chemical vapor deposition of epitaxially grown layers of Group 1-V semiconductor compounds It relates to a method of depositing using a method.

In the development of epitaxial growth technology for conductor compounds in the past decade, many There was something that caught my interest. The best known of these technologies is organometallic This is called chemical vapor deposition (OMCVD).

In carrying out this technique, arsine or arsenic trihydride (AsH3) and Phosphine, hydrides such as phosphorus trihydrate (Pl-43), or these The combination with organometallic compounds such as hydrides is usually used as a source of V1N elements. has been used.

Unfortunately, these techniques are sensitive to the presence of oxygen and water vapor in arsine and phosphine. It has been found that this cannot be completely satisfied as it can easily cause harm. moreover More importantly, the use of these hydrides is likely to cause toxicity problems. It is.

According to the present invention, these prior art limitations are overcome when solid Group V The elemental source is used as a source material in combination with an organometallic compound of a group The m-V group semiconductor compound i (is removed by a process involving the product Ru.

Until now, operators in the prior art have avoided using solid sources for this purpose. I had never seen it before. This is because the vapor of group V elements is the same as that of group It cannot be transported by a method that replaces vapor, and the latter is the vaporization of group V elements. This is because it was widely recognized that it decomposes at high temperatures. we like this The restriction is to initially maintain the vapor flows in different conduits and then to combine them before heating. Group V elements evaporate as the temperature is lowered to a temperature consistent with the vaporized organometallic compound. A with hydrogen! This can be overcome by preventing its concentration in J. I discovered that.

The present invention is illustrated in the accompanying drawing, which illustrates an apparatus suitable for use in an embodiment of the invention. This can be more easily understood by referring to the top view.

Referring to the drawing in more detail, a crystal block 12, a support plate for a substrate wafer 31 and a susceptor 13 and a follower having a crystal support member 30 of the susceptor 13 therein. A conventional cold wall reactor 11 is shown. The reactor 11 has an S pipe 14, an exhaust pipe 15 and and a cap member 16 acting as a seal at the outlet end of the reactor 11. There is. An RF coil 17 is installed in the middle of the reactor 11 for the purpose of heating the susceptor during the reaction. is set up around. A heating tape 18 is also placed at the inlet end of the reactor. It is provided for the purpose of processing to concentrate elements such as group V elements. death Kashiso tape is produced by a parasitic reaction between a group II organometallic compound and a group V element vapor. Do not heat it enough to cause The temperature in this region is 200-300°C.

A vaporizer for vaporizing a Group V feed material as part of an apparatus in the practice of this invention. A blasting furnace 19 is also provided, one having a boat 20 into which the feed material is placed. are doing. The boat 20 is connected to a crystal tube 21 in which a soft iron bar 22 is enclosed. are combined. The hook means 23 connected to the tube 21 is connected to the “!2a buried sequence”. gives magnetic movement of the boat during the process. One furnace similarly seals the conduit 24 and the inlet. and a conduit 2 connected to the conduit 14 of the cold-wall reactor 11. Contains 6. Heating of the source material exiting the furnace 19h1 is carried out around the outlet conduit 26. This is done by means of a wound heating tape 27. Organometallic compounds and hydrogen A conduit 28 for introduction into the reactor 11 is connected to conduits 26 and 14. It is shown.

A brief description of the process according to an embodiment of the invention is given below.

First, MI the desired epitaxial heel on top of it! ? A board member that can perform selected. Substrates suitable for this purpose may be conductive or insulating in nature. The best choice depends on the intended type of device. typical for the purpose Commonly known materials include gallium arsenide, indium phosphide, and similar materials. It is. These substrates are readily available from commercial sources.

Prior to inserting the substrate wafer onto the surface of susceptor 13, the substrate is subjected to conventional degreasing. and an etching process, which ensures a clean surface for deposition. . A typical cleaning process is Iiii! 3:1:1 mixture of I acid, hydrogen peroxide and water Trichlorethylene, acetone and methyl alcohol followed by etching with Includes degreasing with a tool.

Etching continues long enough to remove approximately 2 microns from the substrate surface. . The degreased and etched substrate 31 is placed on the susceptor 13 in the cold wall reactor 11. It will be destroyed.

According to one aspect of the invention, high purity elemental or compound solid state A Group V source material is selected. For this purpose typically 99.9999 % purity is desirable. arsenic, arsenide gallium polycrystalline indium oxide, polycrystalline indium phosphide, polycrystalline indium phosphide, and phosphorus. Usually used for this purpose. The source material selected in this way is then used in the evaporation furnace. It is placed in boat 20 of 19. The weight of the source material is not considered to be a limiting factor. There is only one thing that is necessary (i.e., the presence of the desired Group V compound) There should be enough material v1 to The selected sources were solids from well-known commercial sources. or 41 halogenated compounds such as arsenic trichloride or phosphorus trichloride. Fractionally distill the material and concentrate the arsenic or timilium vapor before depositing it! Ii! to do Generated in a more original form. In the latter case, the furnace 19 is considered movable and the movable boat is excluded. be removed.

] During the two-culm operation, the source material in boat 2o is combined with hydrogen flowing into the furnace from inlet 24. is heated to. Heat hydrogen to reactor 1 at a temperature sufficient to vaporize the solid source. This is done by acting as a means of transporting the vaporized source to 1. steam to be transferred The volume depends on the form and carrier concentration level of the chytria, the morphology and growth of the deposited layer. determine the rate.

Such parameters must be determined experimentally for each system, e.g. The method of application is such that it depends on considerations related to the intended use of the deposited coating. heating The tape 27 is heated to the same temperature as the furnace 19, thereby causing the source to leave the furnace 19. ensuring that the vapor does not condense in the conduit leading into the reactor 11 with cold walls; There is.

At the same time as heating the source material, the hydrogen is heated to a temperature several degrees below air temperature, or At low temperatures depending on the vapor pressure of the organic metal compound, liquid organic metals of group Bubbles can be generated in a compound. This allows the organometallic compound vapor to become a solid source. The growth region in the reactor 11 is passed through a conduit 28 past the region 33 where it joins the steam from the reactor 11. through a conduit 14 leading to the area. Transport of organometallic compounds is possible when hydrogen is transferred to organometallic compounds. This is regulated by controlling the rate at which bubbles pass through the genus compound. Pass the conduit 28 Hydrogen introduced as Ru. Changing the source of Group III compounds during the growth process and/or adding selenized water Suitable dopers for systems such as base metals, silanes, diethylzinc and similar It will be understood by those skilled in the art that it is suitable to add additional components.

The plate material F131 included in the cold wall reactor 11 allows the growth of a desired semiconductor compound. heated to a temperature sufficient to Generally, this temperature is =1.75-750℃ The preferred range found is 600-750°C; is required from considerations related to layer quality.

The epitaxial film prepared according to the above procedure is easily understood by the two speakers. It can be used in a wide range of device applications such as A typical example of such a device is a field effect transistor. transistors, light emitting diodes, lasers, etc.

One embodiment of the invention is described below. This example is for disclosure purposes only. Please understand that this is not intended to be interpreted as limiting.

This example describes the preparation of a gallium arsenide epitaxy 1-nor film using an apparatus of the type shown. Explain growth. The substrate used is t from the (100) crystal plane to the (111) surface. The wafers were semi-insulating chromium-doped gallium arsenide wafers that were offset by 6 degrees toward the surface.

The selected source material is 99.9999% pure elemental hydrogen obtained from commercial sources. It was plain.

The arsenic source material was placed in an evaporation furnace boat and heated to approximately 450°C. cold wall reaction The susceptor in the furnace is then heated to 650°C using high frequency induction, and the susceptor heated a quartz crystal reaction tube on a gallium arsenide wafer with almost no heat loss. It was done. High-purity hydrogen flows at a flow rate of 11/min at 25C at the tip edge of the Zurara susceptor. It passed through the evaporation furnace at a flow rate of m/s. The arsenic transferred to the deposition area is suspended by Hf, and then diffused. 0.025g/min to 0.125g/min corresponding to source temperature 425-475℃ It was within the range of

Hydrogen is bubbled through trimethylgallium and 1-limethylaluminum. The resulting vapor was transferred to a cold wall reactor. 1X1 in the deposition area A partial pressure of trimethylgallium of 0-4 was established as the condition for growth initiation. growth is It was started at a rate of approximately 0.125 μm/min.

The resulting grown layer was of P type and had a carrier density of about 2 x 1015 cm-3. .

By examining the reactions described in the example above, we can see that deposition occurs when solid arsenic is heated. It has become clear that the decomposition reaction of the As4 molecules formed is the dominant factor. This is m product The properties are said to be significantly different from those observed in commonly used arsine. It was discovered that results were obtained.

This conclusion is based on a substrate whose (100) plane is offset by 6° from (100) to (111)A. observed on an epitaxial layer grown, which is P-type when using a solid arsenic source. This is supported by the fact that However, when arsine is used No (100) plane is observed and the resulting layer is similar to typical n-type growth conditions. It's below.

The first advantage of the method described above is that it eliminates the use of highly toxic arsine gas. The point is that you can stop using it. However, ancillary benefits include Group V sources and organic gold Eliminate parasitic reactions between genus compounds, especially noticeable reactions in organometallics including indium. Including.

Finally, optimization of the It product parameters allows the deposition of m-vts compounds and their alloys. It is understood that it is acceptable.

Translation 17 in the amendment (Article 184-7, Paragraph 1 of the Special Revision Act) June 1988 28th Commissioner of the Patent Office Michibu Uga, Prisoner 1. Display of patent application PCT/lJs 85101483 2. Name of the invention Technology for growth of epitaxial compound semiconductor films 3, patent applicant Address: New Chassis, United States of America 07039-2729゜Living 290 Bresant Avenue, West Mount, Stone Name: Bell Communications Research.

incoholated 4. Agent (Postal code 100) 2-3 Shiratama-chome, Maruno, Chiyoda-ku, Tokyo [Telephone Tokyo (211) 2321 Representative] 5. Submission date in the amendment 1986 2, Patent The scope of the claims 1. Epitaxial gallium atom or gallium aluminum arsenide on the substrate The growth method produces arsenic from solid sources in elemental or compound form. forming a vapor stream and adding gallium or a gallium aluminum compound to the first vapor stream; after the first and second vapor streams are combined, the first vapor stream to prevent condensation as the temperature of the second vapor stream decreases to match that of the second vapor stream. diluted with hydrogen in order to 2, characterized in that J is stacked on the substrate, as described in claim 1. In the method described above, the lithium or aluminum compound is an organometallic compound. A method characterized by:

3. The method according to claim 2, wherein the plate is a gallium arsenide wafer. Yes, the arsenic source is elemental arsenic, and the gallium cum compound is trimethylgalium A method characterized in that

4. The method of claim 1, wherein the second vapor stream is the first vapor stream. A method characterized in that the streams are combined with hydrogen to dilute them after their combination.

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Claims (12)

[Claims] 1. Group V source material vapor with Group III compound at compound semiconductor growth temperature a III-V epitaxial semiconductor compound on a substrate, comprising reacting with in which the Group V source material is in elemental or compound form. A method characterized by being in a solid form. 2. The method according to claim 1, wherein the Group III compound is organometallated. A method characterized by being a compound. 3. 2. The method of claim 1, wherein said Group V source material comprises arsenic or is gallium arsenide. 4. The method according to claim 3, wherein the Group III compound is trimethyl A method characterized by being gallium. 5. The method of claim 3, wherein the arsenic is heated to a temperature of about 450°C. A method characterized by being heated. 6. The method of claim 3, wherein the substrate is heated at a temperature in the range of 475-750°C. A method characterized in that the method is heated to a temperature of 7. 7. The method of claim 6, wherein the Group III compound is trimethyl A method characterized by being gallium. 8. The method according to claim 1, wherein the vapor of the Group V diffusion source material is in elemental form. a first vapor stream of a Group V material in solid form; The mixture is in the form of a second vapor stream, and after the first and second vapor streams are combined, , the first vapor stream decreases in temperature to a temperature consistent with the second vapor stream. method, characterized in that it is diluted with hydrogen to prevent condensation. 9. 9. The method according to claim 8, wherein the Group III compound is organometallated. How to be a compound. 10. The method of claim 9, wherein the substrate is a gallium arsenide wafer. , the Group V material is uncombined arsenic, and the Group III compound is A method characterized in that trimethylgallium is used. 11. 9. The method of claim 8, wherein the second vapor stream is A method characterized in that it comprises hydrogen which dilutes the air streams after their merging. 12. 12. The method of claim 11, wherein the substrate is exposed to the combined vapor stream. causing deposition from the vapor flow on the substrate by exposing to How to do it.