JPH0425718B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an indium-antimony-based composite crystal semiconductor and a method for producing a thin film thereof, and more specifically, indium which has high mobility and a Hall coefficient and exhibits properties suitable for a Hall element or a magnetoresistive element when formed into a thin film. - This invention relates to an antimony-based composite crystal semiconductor and a method for producing its thin film. It has been known that indium-antimony compound thin films have extremely high mobility and are suitable as materials for Hall elements and magnetoresistive elements.In particular, they have recently been used as position detection devices for direct drive motors, It has started to attract attention as a component for VCRs and audio equipment. On the other hand, in recent years, there has been an increasing demand for materials with high resistance due to the desire to reduce the power consumption of these parts. However, in order to meet this requirement using conventional materials, it is necessary to increase the length of the element portion, which is contrary to the current demand for miniaturization. Therefore,
It became necessary to increase the resistance of the material itself, and there was therefore a desire for a thin film with high resistance that increased the Hall coefficient without reducing mobility. The present inventor previously proposed an indium-antimony based composite crystal semiconductor which has excellent properties as a material for Hall elements, magnetoresistive elements, etc., and a method for manufacturing its thin film [Patent Application No. 56-46962 (Patent Application No. 56-46962) 1987-162378), 56-50294, (Unexamined Japanese Patent Publication No. 57-162378), 56-50294
-166026), No. 56-177394 (Unexamined Japanese Patent Publication No. 58-78418)
) etc.]. However, this method has the problem that the higher the mobility of the film, the lower the Hall coefficient becomes, and as a result, the resistance becomes smaller as shown in the following equation (). Ri∝R _H /μ _H ... () (In the formula, Ri is resistance, R _H is Hall coefficient, and μ _H is mobility) The present inventors further conducted intensive research on indium-antimony-based composite crystal semiconductors. As a result, we formed an indium-antimony composite crystal thin film with an extremely excessive amount of indium, and then, surprisingly, by depositing at least one element selected from zinc and cadmium, this was achieved. We have discovered that for materials with small band gaps such as indium-antimony composite crystals, the effect of increasing membrane resistance and maintaining high mobility can be obtained very easily.Based on this knowledge, we developed the present invention. It was completed. That is, the present invention consists of a composite crystal of an indium-antimony compound crystal and a simple indium crystal, in which the atomic ratio of total indium to antimony is in the range of 1.1 to 1.7, and at least one selected from zinc and cadmium. An indium-antimony based composite crystal semiconductor characterized by containing one kind of element in the number of atoms of 1.1×10 ¹⁶ cm ^-3 or less, and indium and antimony, the atomic ratio of indium to antimony being in the range of 1.1 to 1.7. and then at least one element selected from zinc and cadmium is deposited on the substrate in an amount of 20% or less based on the amount of atoms of the deposited antimony. The present invention provides a method for manufacturing an indium-antimony-based composite crystal semiconductor thin film consisting essentially of an indium-antimony compound crystal and a simple indium crystal. In the present invention, it is necessary that the atomic ratio of all the indium in the composite crystal, that is, the sum of indium and elemental indium in the indium-antimony compound, to antimony is in the range of 1.1 to 1.7. This is because those within this range exhibit higher mobility than those outside this range and can form a practical thin film. Further, if the atomic ratio is less than 1.1, the film becomes brittle and has a high noise level when processed into a thin film, and if it exceeds 1.7, industrial productivity decreases. A particularly preferable range is 1.2 to 1.6, and within this range, the thin film has good crystallinity and high mobility, as well as low noise level and good uniformity. The composite crystal semiconductor of the present invention contains zinc or cadmium or both elements in an amount of 1.1×10 ¹⁶ cm ^-3 or less in the indium-antimony composite crystal containing extremely excessive indium as described above. There is. When the number of atoms exceeds this amount, the original mobility is significantly reduced due to deterioration of crystallinity of the indium-antimony composite crystal formed previously. In order to contain the above amount of zinc or cadmium or both elements in the present invention,
Zinc or cadmium or both in an amount of 20% or less, preferably 2 to 10% based on the amount of atoms relative to the antimony, is added to the previously formed thin film of a composite crystal of an indium-antimony compound containing elemental indium. All that is required is to vapor-deposit the elements. Generally, it is quite difficult to introduce such elements into thin films of grown crystals due to their small adhesion coefficients, but in the thin films of the present invention, the presence of excess molten indium The elements are introduced in an amount approximately proportional to the amount of vapor deposition. That is, in the present invention, it is important to form an indium-antimony composite crystal thin film in which the atomic ratio of indium to antimony is in the range of 1.1:1 to 1.7:1. Such an indium-antimony composite crystal thin film was produced by the method previously proposed by the present inventors (Japanese Patent Application No. 1983).
-46962, No. 56-50294, No. 56-177394, etc.), it can be easily formed by controlling the amount of indium and antimony deposited using a vapor deposition method. Further, this crystal thin film can be formed as a highly grown crystal thin film depending on the deposition conditions, particularly the substrate temperature. Among these, in order to obtain a thin film with high mobility, measures such as increasing the substrate temperature are particularly useful. In the present invention, first, indium and antimony are heated at usually 300 to 520°C so that the atomic ratio of indium to antimony is in the range of 1.1 to 1.7.
on a substrate kept at a temperature range of preferably 1.0
Vapor deposition is performed at a deposition rate in the range of ~10 Å/sec, and then, at an appropriate substrate temperature, zinc or cadmium, or both elements, are added to the deposited antimony in an amount of 20% or less based on the amount of atoms. Deposit in quantity. The content of these elements in the thin film is significantly influenced by the substrate temperature and the vapor pressure of those elements. For example, at a high substrate temperature such as 400°C, the above elements hardly enter the thin film, while at a low substrate temperature such as 200°C, the content of the above elements in the thin film is proportional to the amount of flying. . On the other hand, as described above, since it is necessary to maintain the molten state of indium, the substrate temperature needs to be equal to or higher than the melting point of indium, 157°C.
In addition, when both elements of zinc and cadmium are vapor-deposited, they may be vapor-deposited separately, or
Alternatively, they may be deposited simultaneously. The indium-antimony-based composite crystal semiconductor thus obtained must contain zinc, cadmium, or both elements in an amount of 1.1×10 ¹⁶ cm ^-3 or less, and this amount If the content exceeds the above, the crystallinity of the previously formed indium-antimony composite crystal thin film will be destroyed and the mobility will be reduced, as described above. When using this indium-antimony-based composite crystal semiconductor as a highly sensitive Hall element or magnetoresistive element, it is preferable to form it into a thin film. Therefore, in order to use the semiconductor of the present invention as a Hall element or a magnetoresistive element, the film thickness must be
It is desirable to form a thin film within the range of 5000 Å to 10 μm, preferably 0.8 to 5.0 μm. The thinner this film is, the higher the output voltage will be, but if it becomes too thin, the mobility will decrease. The indium-antimony-based composite crystal semiconductor of the present invention is usually commercialized in the form of being supported on an insulating substrate, preferably a crystalline substrate. Such substrates include, for example, quartz glass, borosilicate glass,
Sodium glass, saphire, calcium fluoride, sodium chloride, mica, gallium arsenide, etc. are used. The thus obtained composite crystal semiconductor thin film of the present invention can be used as it is, or by pasting or transferring it to another substrate such as ferrite, patterning it, and attaching electrodes to it, so that it can be used as a Hall element or a magnetoresistive element. can be processed into semiconductor devices. Furthermore, the thin film of the present invention has a mobility of 50,000, for example.
cm ² /v.sec and a Hall coefficient of 900 cm ³ /C, which is extremely excellent, and devices using this thin film exhibit extremely high sensitivity even with extremely weak currents. Next, the present invention will be explained in more detail with reference to Examples. Example 1 Vapor deposition was performed using a vacuum evaporation apparatus in which six wafers could be placed concentrically and had a rotating substrate holder. The substrate temperature was sensed by a platinum-palladium thermocouple placed 10 mm above the wafer, and another thermocouple was provided for control. Mica was used as the substrate. The raw materials indium and antimony are both 6-N manufactured by Furuuchi Chemical Co., Ltd.
I used the one from For vapor deposition, first set the vacuum level to 7×10 ^-5 torr.
The substrate temperature was set to 430℃, and the deposition time was 30℃.
The final temperature was brought to 510°C in minutes. Then, the substrate temperature increase rate during that time was determined from 0 to 10 minutes and 12 to 20 minutes after the start of vapor deposition.
minutes, 1-2℃/min for 22-30 minutes, 12-2℃/min for 10-12 minutes
14°C/min, and 6-7°C/min for 20-22 minutes.
Furthermore, for the first 6 minutes, more antimony than indium was allowed to reach the substrate, and 1.2 g of antimony and 1.9 g of indium were evaporated. Next, the substrate temperature was lowered to 210° C., and 0.046 g of zinc was deposited in 4 minutes. The resulting film had a mobility μ _H of 53000 cm ² /v.sec and a Hall coefficient R _H of 880 cm ³ /C. Atomic absorption analysis of three wafers of these films revealed that the atomic composition ratio of indium and antimony was
F _Io /F _Sb was 1.30±0.03. If zinc is not deposited, R _H is 380cm ³ /C.
It was hot. Examples 2 to 4 Vapor deposition was performed in the same manner as in Example 1, except that the vapor deposition method was changed. The results are shown in Table 1.

[Table] Example 5 Cadmium was deposited in the same manner as in Example 1, except that zinc was replaced with cadmium. The amount of evaporated at this time was 1.82 indium.
g, antimony 1.23g, and cadmium 0.051g. The _μH of the obtained film is 34000cm ² /V.sec, and _{the RH} is
It was 650cm ³ /C. Comparative example: The amount of evaporation was 1.9 g of indium, 1.9 g of antimony,
Zinc was deposited in the same manner as in Example 1 using 0.035 g.
The μ _H of the obtained film is 3500 cm ² /V・sec, and the R _H is 230.
cm ³ /C and F _Io /F _Sb were 1.0. Example 6 In Example 1, the reference temperature for zinc evaporation was
The same procedure as in Example 1 was carried out except that the temperature was changed to 300°C. The amounts of indium, antimony, and zinc deposited at this time were 1.85g, 1.3g, and 0.036g, respectively.
It was hot. The properties of the obtained film are μ _H 51000cm ² /V・sec, R _H
495 cm ³ /C, and F _Io /F _Sb was 1.18. In addition, R _H when zinc is not deposited is 350cm ³ /C
It was hot. Example 7 In Example 6, the substrate temperature during zinc deposition was
When the temperature was 400°C, R _H was 360cm ³ /C.

Claims (1)

[Claims] 1. Comprised of a composite crystal of an indium-antimony compound crystal and a simple indium crystal, the atomic ratio of total indium to antimony is in the range of 1.1 to 1.7, and is selected from zinc and cadmium. At least one element, 1.1× the number of atoms
An indium-antimony-based composite crystal semiconductor characterized by containing 10 ¹⁶ cm ^-3 or less. 2. The semiconductor according to claim 1, which is in the form of a thin film. 3. Indium and antimony are deposited on the substrate so that the atomic ratio of indium to antimony is in the range of 1.1 to 1.7, and then at least one element selected from zinc and cadmium is deposited on the substrate.
For antimony deposited, based on the amount of atoms, 20
1. A method for producing an indium-antimony-based composite crystal semiconductor thin film consisting essentially of an indium-antimony compound crystal and a simple indium crystal, the film being deposited in an amount of less than %.