JPS59111321A - Compound semiconductor thin-film structure and its manufacture - Google Patents

Abstract

PURPOSE:To improve reliability and heat-resisting property, and to process elements of various forms by laminating a compound semiconductor thin-film on a substrate through an adhesive resin layer and a glass layer, a thermal expansion coefficient thereof at the normal temperature is kept within a specific range. CONSTITUTION:The titled structure is manufactured by executing a process in which the compound semiconductor thin-film is grown on the substrate for growing a crystal of a selectively removable compound semiconductor, a process in which the glass layer, the thermal expansion coefficient thereof at the normal temperature is kpt within a range of 30X10<-7>/K-70X10<-7>/K, is formed on the compound semiconductor thin-film, a process in which the glass layer is bonded with a base body by an adhesive resin and a process in which the substrate for growing the crystal of the compound semiconductor is removed selectively. A substrate, through which the crystal of the compound semiconductor thin-film is grown excellently and the compound semiconductor thin-film is not attached strongly or the compound semiconductor thin- film is dissolved in a solution, into which the thin-film is not dissolved, and which is crystallized, is preferable as the substrate for growing the crystal of the selectively removable compound semiconductor, and mica, etc. are cited. A substance such as GaP, particularly, one of the low melting point, is effective as the compound semiconductor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly reliable compound semiconductor thin film structure and a method for manufacturing the same.

BACKGROUND ART Conventionally, the following three methods are known as methods for manufacturing compound semiconductor thin film structures. That is, as a first method, Or-doped semi-insulating GaA
Vapor deposited on substrates with excellent crystallinity such as S and sapphire and good operability? This is a method of forming a compound semiconductor thin film using FMBK, OVD, etc. to form a structure. However, this method often requires complicated surface treatment immediately before forming the compound semiconductor thin film, and the types of substrates that can be used are limited in order to match the lattice constants. It has the disadvantage of being expensive.

A second method is to form a compound semiconductor thin film on an amorphous substrate such as glass by a method such as vapor deposition or CVD to form a structure. However, this method has the disadvantage that the compound semiconductor thin film formed on the amorphous substrate generally does not have good crystallinity, and requires complicated post-processing to improve the crystallinity. There is.

A third method is to use evaporation or MBE+C! on a crystalline substrate that can selectively remove compound semiconductors such as mica, chloride, IJ, potassium bromide, etc. After forming a compound semiconductor thin film by a method such as VD, bonding the compound semiconductor thin film to a substrate using an adhesive such as an epoxy resin, and then physically or chemically removing the crystalline substrate to form a structure. It is a method of manufacturing the body (Special Publication Act 1977).
-45234 publication, etc.). However, this method (so-called transfer method) has the disadvantage that reliability, especially heat resistance and moisture resistance, is poor because the resulting structure has an organic adhesive layer such as epoxy resin or phenol resin. .

The inventors of the present invention have conducted intensive studies on how to overcome these drawbacks and obtain a highly reliable structure. As a result, the transfer method has found that the crystal growth substrate and the base body can be separated in the production of the structure. Instead, we focused on the fact that a thin film with excellent crystallinity could be combined with a wide variety of substrates, and by providing a glass layer whose coefficient of thermal expansion matched that of the compound semiconductor thin film between the thin film and the adhesive resin layer, The inventors have discovered that the object can be achieved, and have completed the present invention based on this knowledge.

That is, in the present invention, the adhesive resin layer on the substrate has a thermal expansion coefficient of 30×10 / to 70×10 −
The object of the present invention is to provide a compound semiconductor thin film structure characterized in that compound semiconductor thin films are laminated via glass layers within a range of 7/.

In the structure of the present invention, by selecting and providing the glass layer whose thermal expansion coefficient matches that of the compound semiconductor thin film, the reliability of the structure having the organic adhesive resin layer can be improved. can be dramatically improved. If the thermal expansion coefficients of the two do not match, the thin layer may peel off during high temperature treatment, or wrinkles may occur in the thin film when the heating power is too high.

The structure of the present invention includes a process of growing a compound semiconductor thin film on a selectively removable compound semiconductor crystal growth substrate, and a process in which the compound semiconductor thin film has a thermal expansion coefficient of 30 x 10 / to 70 x 10 at room temperature. -77, a step of adhering the glass layer to a substrate with an adhesive resin, and a step of selectively removing the substrate for crystal growth of the compound semiconductor. be able to.

Next, an outline of an embodiment of the present invention will be explained with reference to the accompanying drawings. FIG. 1 shows a compound semiconductor thin film grown on a selectively removable compound semiconductor crystal growth substrate. 1 is a crystal growth substrate, and 2 is a compound semiconductor thin film. FIG. 2 shows a state in which a glass layer 3 is further formed, and FIG. 3 shows a state in which the glass layer 3 is adhered to a base body 5 via a resin layer 4. Next, FIG. 4 shows the structure of a compound semiconductor thin film structure of the present invention obtained by selectively removing the crystal growth substrate 1 from the structure shown in FIG.

The selectively removable compound semiconductor crystal growth substrate used in the method allows the compound semiconductor thin film crystal to grow well;
Moreover, it is preferable that the compound semiconductor thin film is not strongly adhered to or that can be dissolved in a solution that does not dissolve the compound semiconductor thin film, and that it is crystalline. Examples of such materials include mica, graphite, sodium chloride, potassium chloride, potassium bromide, sodium iodide, alum, and the like.

Further, as the compound semiconductor used in the present invention, for example, G
aP, GaAs, Garb, Ink, InA
s, InSb and In GaxP, In Ga
x As s ENG n1x1-X
l -XGaXSb% oa, -xAzxpt G
a, -xAtXAB, Ga, -XAtxSb, G
aAs, -xPx, GaAs, -xSbx, Ga
rb, -xPx, InAs Px, InAs
, -xSbx, ■nSb, -XPx -X, etc. Among these, GaEI, which has a particularly low melting point,
b, InAs, InSb and In, -x GaxS
b, Engineering nA s r xSbx, InSb, -xPx
etc. are valid.

In order to form a compound semiconductor thin film on the compound semiconductor crystal growth substrate described above, vapor deposition (heater heating, K
Methods such as B heating), MBE, sputtering, and OVD are used. At this time, the thickness of the thin film is preferably in the range of 200 μm to 10 μm, and in consideration of ease of transfer and characteristics, the range 75 = 500 μm to 2 μm is preferable.

The glass layer interposed between the compound semiconductor thin film and the adhesive resin layer in the present invention must be selected from glass compositions that are electrically insulating and whose coefficient of thermal expansion matches that of the compound semiconductor thin film. , in the present invention, the coefficient of thermal expansion of the glass layer at room temperature is 30 x 10-7/
It is sufficient if it is within the range of ~70 x 10-7/. That is, the linear thermal expansion coefficient of the compound semiconductor thin film used in the present invention is:
In the temperature range from room temperature to 500°C (is within the above range. For example, InP (45X 10-7.IK),
Engineering nsb (50X l O'-7/K), GaAs
(60X l O-7/K) etc. are listed as having a typical coefficient of linear thermal expansion at room temperature.

This glass layer has a thermal expansion coefficient of 30 at room temperature.
If a material that deviates from the range of X 10-7/ to 70 Many pinholes occur during adhesion. In the present invention, a particularly preferable glass layer has a coefficient of thermal expansion VC of ±l OX of a compound semiconductor thin film.
It is desirable to use a glass composition having a thermal expansion coefficient of 1 O-7/. Examples of such glass compositions include borosilicate glasses and alumina silicate glasses.

In the present invention, the first reason for interposing the glass layer between the compound semiconductor thin film and the adhesive resin layer is to prevent mutual diffusion between the thin film and the resin.

For example, by providing a glass layer, undesirable impurities in the adhesive resin may diffuse into the thin film, or elements constituting the thin film may diffuse into the adhesive resin and the composition may change.
It is possible to prevent the phenomenon of peeling caused by a decrease in film thickness. It's a trench.
The second reason is to relax thermal stress. That is, the compound semiconductor thin film is 40 x 10-7/~60
In general, adhesive resins have a thermal expansion coefficient of about 1 x 10-5/
/ ~ 7 The above thermal stress is alleviated by interposing the glass layer between the three.However, if the thermal expansion coefficient of the glass layer does not match that of the compound semiconductor thin film,
Thermal stress may occur at the interface between the glass layer and the thin film, or the adhesion may deteriorate and peel, resulting in deterioration of the heat resistance properties of the structure.

In the present invention, the thickness of this glass layer is 500 mm to 5 mm.
It is desirable that the thickness be within the range of 500 μm.
If the thickness is less than X, the effect of the present invention will not be seen, and if it exceeds 5 μm, it will often peel off or a large number of pinholes will be generated after the substrate is selectively removed. The preferred thickness of the glass layer is in the range of 1000 to 500X.

Methods such as E, B, vapor deposition, sputtering, and CvD can be used to form this glass layer on the compound semiconductor thin film. Among these methods, sputtering, which has good adhesion to the thin film, can be used. is preferably used. However, if the layer thickness is not required so much, E, B, vapor deposition, etc. may be used without any problem.

The adhesive resin used in the present invention preferably has good adhesion to the glass layer and has a relatively high heat distortion temperature. Examples of such resin include epoxy 7 resin, polyimide resin, polyamideimide resin, etc. can be mentioned. Further, these resins preferably do not unnecessarily contain impurities that have a doping effect on the compound semiconductor thin film, reactive fillers, and the like.

Next, the substrate used in the present invention may be any material as long as it can withstand the treatment of the adhesive resin (at the time of ashing, the time of device heating, and the processing after device formation), and is particularly chemically stable and at -100°C.
Preferably, the material does not undergo thermal deformation in the temperature range from 400°C to 400°C. These include precious metals and inorganic materials such as ceramics, such as gold, silver, platinum, permalloy, centerst, alumina, ferrite, silicon nitride, quartz,
Examples include sapphire, borosilicate glass, and alumina silicate glass.

Removal of the crystal growth substrate from the structure of the present invention is performed by a physical or chemical method, although it varies depending on the type of substrate used. For example, when mica is used as the substrate, the substrate can be mechanically peeled off from the compound semiconductor thin film adhered to the substrate, and when sodium chloride is used, only the sodium chloride can be dissolved using water. .

The structure of the present invention has excellent reliability, and in particular has remarkable improvement in heat resistance compared to conventional structures. Therefore, when used as an element, treatments such as solder dipping at 260° C. for 5 seconds and/or soldering at a temperature of 300° C. can be performed.

Further, the structure of the present invention can be processed into various types of elements. That is, magnetoelectric conversion elements (Hall elements, Hall heads, magnetoresistive elements, etc.), junction transistors, field effect transistors, electrostatic three-conductor transistors, piezoelectric elements, light emitting elements, light receiving elements, moisture sensing elements, humidity sensing It is also possible to integrate the elements into an IC (integrated circuit).

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Mica was used as a substrate for crystal growth, and a vacuum evaporation apparatus having two boats was used as a compound semiconductor thin film forming apparatus to perform vapor deposition of Sb and Sb.

At this time, the substrate temperature was set to 440°C, the degree of vacuum was set to i, and 5xio-
6 TOrr and 1μ in 30 minutes, In
A Sb-based composite crystal thin film was manufactured.

Furthermore, on this thin film, Corning 7059 glass (
Osilicate glass, coefficient of linear thermal expansion 47X10-7iK>
*- Sputtered to form a 4200X thick glass layer.

Next, Epogin resin (manufactured by Japan Bell 7 Sox Co., Ltd., XM188
0) to form a nsb-based thin film through a glass layer.
After adhering to a 5 mm thick ferrite plate, the mica was mechanically peeled off to obtain an InSb-based thin film structure.

After patterning this structure using techniques such as photolithography and processing it into the shape shown in Figure 5, we measured the electrical properties of this thin film and found that the Hall coefficient was 210.
CJ/C, electron mobility 19,800cm/V-13
Met.

This structure was treated in a nitrogen atmosphere at 350° C. for 30 minutes, and the change rates of the Hall coefficient and electron mobility were determined to be +1.0% and −5%, respectively.

Comparative Example 1 I was prepared in the same manner as in Example 1 except that the glass layer was not provided.
Creation of nSb-based thin film structure 1-1 350℃ under nitrogen atmosphere
When the rate of change in properties before and after treatment at 30°C was examined, the rate of change in Hall coefficient was 11.5%, and the rate of change in electron mobility was -5.6%.

Example 2 A thin film structure was produced in the same manner as in Example 1, except that 7059 galanu was vapor-deposited using E and B to form a glass layer with a thickness of 1700 mm. Using this structure, we made 400 Hall elements and conducted a solder tip test at 260°C for 5 seconds to determine the change in constant voltage sensitivity before and after, and found that the average -
The standard deviation for the 0.1 ratio was 2.6%.

For comparison, a similar test was conducted using a structure without a glass layer, and the change in constant voltage sensitivity was found to be -2.4% on average, with a standard deviation of 3.3%. .

Example 3 An InSb-based thin film was formed in the same manner as in Example 1, and then 1723 Karas (alumina silicate, 4
2 x 10"-7/K) by sputtering to 280
A 0X thick glass layer was formed. Next, an NSB-based thin film structure was prepared using FC.

When this structure was processed into the pattern shown in FIG. 5 and its characteristics were determined, the Hall coefficient was 307 cnl/O, and the electron mobility was 27, 600 crl/V, S.

In addition, after processing this structure in a wholesale atmosphere at 350°C for 30 minutes, we determined its characteristics, and found that the Hall coefficient was 3.
08 ctd/ O1 electron mobility 27,600 C/V
, S.

Example 4 Mica was used as the deposition substrate and a vacuum deposition apparatus having three boats was used to deposit buttons, sb, and 88. During this time, the substrate temperature was increased from 400°C to 55°C in 40 minutes.
In'sbo, heated to 0°C and 1.2 μm thick, A
So, a thin film was obtained.

This thin film was coated with Corning's 7052.1723.77.
40 glass was sputtered to a thickness of 2,500 x each, and FC...-do XV manufactured by Shikoku Kasei Co., Ltd. was used as the adhesive resin.
Three types of In5bAs-based thin film structures bonded to ferrite plates were manufactured using 1161.

The heat resistance characteristics of each of these structures were evaluated at 380 °C under a nitrogen atmosphere.
It was determined by processing at ℃ for 30 minutes. The results are shown in Table 1.

Table 1 Comparative Example 2 A thin film structure was produced in the same manner as in Example 4 except that Corning 6720.7900 was used as the glass,
The heat resistance properties of this material were determined. The results are shown in Table 2.

Table 2 Example 5 An In5b composite crystal thin film was produced in the same manner as in Example 1 using IJ (chloride) as a substrate for crystal growth. Corning Co., Ltd. as in Example 1 was applied on the InSb composite crystal thin film formed on the sodium chloride. L
'OSC+ glass was sputtered to form a glass layer with a thickness of 5200X, and then transferred onto a 0.5X ferrite plate using AER331 manufactured by Asahi Kasei, and the sodium chloride was removed using water. When this structure was processed into a Hall element, the sensitivity of 100 pieces was measured, and it was 39 to 53 mV / 5 mAx IK, Gauss
Met. The humidity test of this element was carried out at a temperature of 65℃ and a humidity of 9.
When a dry/wet cycle of 7% for 12 hours and 25° C. and 65% for 12 hours was repeated 15 times, the sensitivity change rate of 91 of them was within 2%.

Comparative Example 3 100 Hall elements were manufactured in the same manner as in Example 5 except that 7900 glass manufactured by Corning Corporation was used as the glass layer, and the same test was conducted, and 74 of them had a sensitivity change rate of 2. It was within %.

Example 6 The same substrate and device as in Example 4 were used, and In, G
Gao, 3Ino, and 7Sb thin films were formed by vapor deposition of a and sb. At this time, the substrate temperature ranges from 410°C to 550°C.
The deposition time was 35 minutes, and the film thickness was 1.5 μm according to the heating method up to ℃. Next, Corning 1720 glass (alumina silicate, thermal expansion coefficient 42X10-7/K
) was sputter-linked to form a glass layer with a thickness of 2200X, and then transferred to a ferrite plate using TVB 2703 manufactured by Toshiba Chemical Corporation.

Ten pieces of this structure were processed into the shape shown in Fig.
When the rate of change of input resistance and constant voltage sensitivity was calculated, they were A-4, 8 to 5.1%, -4, 7 to 2.1%, and 4.
Despite the treatment at 00°C, the rate of change showed good heat resistance with a maximum factor of 5.

Comparative Example 4 Example 6 was carried out in the same manner as in Example 6, except that a 2600× thick 5102 layer was formed by sputtering as the glass layer. After heat treatment at 400° C., many pinholes were generated in the electrode portion.

Example 7 The substrate and apparatus were the same as in Example 1, and In and AS were deposited using a three-temperature deposition method. The obtained InAs-based thin film had an electron mobility of 4200 cA/V, S. This InAs thin film (thermal expansion coefficient 52X10-7/K
), Corning's 7056 glass (borosilicate, thermal expansion coefficient 51 x 10'/K) was placed at 3800λ
After sputtering thickly, it was transferred to an alumina plate using TVB 2703.

After processing this structure into the shape shown in Fig. 5, it was heat-treated at 400°C in a nitrogen atmosphere and the rate of change in characteristics was determined. There was◇

[Brief explanation of drawings]

Figure 1 shows a compound semiconductor thin film grown on a selectively removable compound semiconductor crystal growth substrate, Figure 2 shows a state in which a glass layer is further formed, and Figure 3 shows a state in which a glass layer is grown through a resin layer. FIG. 4 is a cross-sectional view of the compound semiconductor thin film structure of the present invention obtained by selectively removing the substrate for crystal growth from the structure shown in FIG. In the figure, reference numeral 1 indicates a substrate for crystal growth, 2 indicates a compound semiconductor thin film, 3 indicates a glass layer, 4 indicates a resin layer, and 5 indicates a substrate. In the figure, symbols a and a' are input electrodes, and b and b' are output electrodes. Patent applicant Asahi Kasei Industries Co., Ltd. Agent Akira Agata Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Procedure correction April 1, 1982 3 Relationship with party making the amendment f4 Patent applicant address 1-2-6 Dojima 1-chome, Kita-ku, Osaka-shi, Osaka Representative Nagisa Teru Miyazaki 46th Masato Address 104 Tokyo Tsuchiya Pinoshi 5, 6-4-5 Ginza, Chuo-ku, Tokyo
Floor 8, Contents of amendment ([) [ooo ~ 500] on page 9, line 15 of the specification
Correct 0XI to 1700-5000AJ. (2) Page 17, line 7 [5200AJ is replaced with “12
Corrected to 00A.

Claims (1)

[Claims] 1. A compound semiconductor thin film is laminated on a substrate via an adhesive resin and a glass layer whose thermal expansion coefficient at room temperature is within the range of 30X10-7/ to 70X10-7/. A compound semiconductor thin film structure characterized by: 2. A step of growing a compound semiconductor thin film on a selectively removable compound semiconductor crystal growth substrate, and growing a compound semiconductor thin film on the compound semiconductor thin film with a thermal expansion coefficient of 30 x 10-7 at room temperature.
A step of forming a glass layer within the range of / to 70 x 10-7/, a step of adhering the three glass layers to a substrate with an adhesive resin, and selectively removing the substrate for crystal growth of the compound semiconductor. A method for manufacturing a compound semiconductor thin film structure, comprising the steps of: