JP4992080B2 - Semiconductor manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor for manufacturing a photoelectric conversion functional element such as a light emitting diode or a laser diode, and particularly to a method for manufacturing a p-type or n-type zinc telluride (hereinafter referred to as ZnTe) thin film.

  In the conventional method for producing a p-type II-VI compound semiconductor, a hydrogen atom and a nitrogen atom taken together with a nitrogen atom as an acceptor impurity in the II-VI compound semiconductor during the growth of the II-VI compound semiconductor. A heat treatment is performed at a temperature of 650 to 850 ° C. in order to break the bond and release the hydrogen atom as a hydrogen molecule to the outside. Further, in order to prevent the constituent elements of the II-VI group compound semiconductor from evaporating or surface roughness during this heat treatment, among the Group II elements and Group VI elements constituting the II-VI group compound semiconductor, This heat treatment is performed in a gas atmosphere containing at least a Group II element or a Group VI element having the highest vapor pressure (see, for example, Patent Document 1).

In addition, the target raw material gas is different from the ZnTe thin film manufacturing method according to the present invention. However, in the conventional nitride semiconductor manufacturing method, an organic metal and ammonia gas containing In, Ga, and Mg, respectively. A 20 nm AlN buffer layer grown on a sapphire substrate at 550 ° C. is provided on the sapphire substrate using an organic metal vapor phase growth method using nitrogen gas as a carrier gas and 1000 ° C. on the AlN buffer layer. A grown GaN buffer layer of 1100 nm is provided, grown on the GaN buffer layer at a growth temperature of 780 ° C., and subjected to a heat treatment at 500 ° C. or higher in a nitrogen atmosphere so that hydrogen atoms captured in the InGaN during growth are removed. There is a p-type nitride semiconductor provided with the extracted Mg-doped InGaN layer (for example, Patent Document 2).
Japanese Patent Laid-Open No. 08-130188 (page 7, right column, lines 6-22), FIG. 4) JP 2001-1119013 (page 4, left column, lines 5 to 39, FIGS. 1 and 2)

  In order to obtain a p-type II-VI group compound semiconductor having a sufficiently high carrier concentration, a conventional semiconductor manufacturing method includes at least one nitrogen atom as a p-type dopant, and the molecular weight of the nitrogen atom is at least greater than 12. An organic compound in which at least two large groups are bonded is used. For this reason, it becomes necessary to remove the bond between the hydrogen atom incorporated together with the nitrogen atom as the acceptor impurity and the nitrogen atom to release the hydrogen atom to the outside as a hydrogen molecule, and heat treatment is performed at a high temperature of 650 to 850 ° C. In addition, heat treatment is not performed in a gas atmosphere containing at least a Group II element or a Group VI element having the highest vapor pressure of the Group II element and the Group VI element constituting the Group II-VI compound semiconductor. There was a problem that it should not.

  The present invention has been made to solve the above-described problems. In a semiconductor in which ZnTe is formed on a substrate, a semiconductor having a high carrier concentration even when a general impurity is used as a dopant. The manufacturing method of this is provided.

In the method for manufacturing a semiconductor according to the present invention, a p- type zinc telluride doped with phosphorus is formed on a substrate by metal organic vapor phase epitaxy, and the p-type zinc telluride is formed. the film was the substrate, in an atmosphere of a gas which does not react with the zinc telluride of the p-type, and a heat treatment step of annealing, a p-type zinc telluride thin film was deposited on a substrate in the film forming process is A thermal diffusion treatment step comprising: a plurality of layers having a hole concentration decreasing from the substrate toward the surface, and thermally diffusing impurities for diluting the hole concentration from the surface to the p-type zinc telluride thin film; , With .

Moreover, in the semiconductor manufacturing method according to the present invention, the heat treatment temperature in the heat treatment step is set to be equal to or lower than the film formation temperature in the film formation treatment step, as necessary .

Also, in the method of manufacturing a semiconductor according to the present invention, if necessary, before Symbol impurity is aluminum.

In the method for manufacturing a semiconductor according to the present invention, a p- type zinc telluride doped with phosphorus is formed on a substrate by metal organic vapor phase epitaxy, and the p-type zinc telluride is formed. the film was the substrate, in an atmosphere of a gas which does not react with the zinc telluride of the p-type, and a heat treatment step of annealing, a p-type zinc telluride thin film was deposited on a substrate in the film forming process is A thermal diffusion treatment step comprising: a plurality of layers having a hole concentration decreasing from the substrate toward the surface, and thermally diffusing impurities for diluting the hole concentration from the surface to the p-type zinc telluride thin film; , The carrier concentration and the photoluminescence intensity (light emission intensity) can be increased as compared with a ZnTe thin film that is not subjected to heat treatment. In addition, the semiconductor manufacturing method according to the present invention can be easily formed on a substrate as compared with a thin film of n-type ZnTe which is difficult to control the conductivity type due to the effect of self-compensation and residual impurities. it can. Further, the semiconductor manufacturing method according to the present invention is advantageous for producing high-quality crystals and is excellent in mass productivity. In the method for manufacturing a semiconductor according to the present invention, a semiconductor layer having a steep impurity distribution can be formed, which can lead to higher performance in manufacturing an electronic device such as a light emitting device. Further, it can be easily formed on a substrate as compared with other thin film manufacturing methods.

  In the method for manufacturing a semiconductor according to the present invention, if necessary, the heat treatment temperature in the heat treatment step is set to be equal to or lower than the film formation temperature in the film formation step, so that the constituent elements of the ZnTe thin film can be reduced during the heat treatment step. Evaporation and surface roughness can be prevented.

Further, in the semiconductor manufacturing method according to the present invention, if necessary, before Symbol impurities by aluminum, as compared to other thin film forming method, it can be easily fabricated on the substrate.

(First embodiment of the present invention)
FIG. 1 is a schematic configuration diagram showing a heat treatment apparatus used in the first embodiment for carrying out the present invention, FIG. 2 is a graph showing a change in electrical characteristics of a ZnTe thin film by heat treatment with a constant heat treatment time, and FIG. FIG. 4 is a room temperature photoluminescence characteristic diagram showing a change in the photoluminescence spectrum of a ZnTe thin film at room temperature by a heat treatment with a constant heat treatment time. FIG. 5 is a photoluminescence characteristic diagram showing a change in the photoluminescence spectrum at 4.2 K of a ZnTe thin film by heat treatment at a constant heat treatment temperature, and FIG. 6 is a wavelength region of 520 to 520 in the characteristic diagram shown in FIG. It is the characteristic view which expanded 540 nm.

  In FIG. 1, a substrate 1 to be processed is obtained by growing a ZnTe thin film 1b on a substrate 1a by using a molecular beam epitaxial growth method, a metal organic chemical vapor deposition method or the like. As the substrate 1a, a gallium arsenide (GaAs) substrate, an indium phosphide (InP) substrate, a silicon (Si) substrate, a sapphire substrate, a silicon carbide (SiC) substrate, and the like are used in addition to a ZnTe substrate.

  In the ZnTe thin film 1b, the Zn source gas is not particularly limited as long as it contains Zn and can be formed into a ZnTe film by molecular beam epitaxy or metal organic vapor phase epitaxy. Examples thereof include dimethyl zinc (DMZn), diethyl zinc (DEZn), and diethyl zinc triethylamine (DMZn-TEN).

  The Te source gas is not particularly limited as long as it contains Te and can form a film of ZnTe by molecular beam epitaxy, metal organic vapor phase epitaxy, or the like. Diethyl tellurium (DETe) , Diallyl tellurium (DATe), and diisopropyl tellurium (DiPTe).

  Furthermore, examples of the p-type dopant include arsenic (As), antimony (Sb), phosphorus (P), lithium (Li), and nitrogen (N). Examples of the n-type dopant include aluminum (Al) and chlorine (Cl). Etc.

  The substrate 1 to be processed in the first embodiment includes dimethyl zinc (DMZn), which is a Zn source gas, diethyl tellurium (DETe), which is a Te source gas, and phosphorus (P), which is a p-type dopant. Is a semiconductor in which a p-type ZnTe thin film 1b is grown on a ZnTe single crystal substrate, which is a substrate 1a, using a metal organic vapor phase epitaxy method in a chamber into which a doping gas containing as a constituent element is introduced. The substrate 1a, the source gas and the dopant, and the metal organic vapor phase epitaxy method are not limited, and any substrate on which ZnTe is formed by a conventional film formation process may be used.

  The heat treatment apparatus 2 heats the inside of the quartz tube which is the treatment chamber 3 until it reaches a temperature at which the substrate 1 to be treated is annealed in a heat treatment step to be described later (hereinafter referred to as a heat treatment temperature) by an electric furnace 4. The inside of the processing chamber 3 can be kept at the heat treatment temperature. In order to make the inside of the processing chamber 3 a gas atmosphere that does not react with ZnTe, a gas that does not react with ZnTe is introduced from the gas inlet 5. Further, unnecessary gas is exhausted from the exhaust port 6.

Next, the heat treatment process in the first embodiment of the present invention will be described.
First, a gas that does not react with ZnTe is introduced into the processing chamber 3 from the gas inlet 5. Here, the gas that does not react with ZnTe is a rare gas such as helium, neon, argon, krypton, xenon, or radon, or an inert gas such as nitrogen. In the first embodiment, nitrogen is used. is doing.

  In addition, the gas that does not react with ZnTe introduced into the processing chamber 3 may be heat-treated on the substrate to be processed 1 in a sealed state in the processing chamber 3 without being exhausted from the exhaust port 6. The substrate to be processed 1 may be heat-treated in a flow state in which it is introduced from the gas inlet 5 and discharged from the outlet 6 by exhausting from the gas inlet 6.

  Next, the inside of the processing chamber 3 is heated by the electric furnace 4 until the heat treatment temperature is reached, and the inside of the processing chamber 3 is controlled to keep the heat treatment temperature. Here, the heat treatment temperature is equal to or lower than the temperature at which ZnTe is formed on the substrate 1a in the film forming process described above (hereinafter referred to as film forming temperature), that is, the temperature of the heated substrate 1a during the growth of the ZnTe thin film. The upper limit is controlled. In the first embodiment, the upper limit of the heat treatment temperature is 500 ° C., but it is possible to prevent the constituent elements of the p-type ZnTe thin film 1b from evaporating or causing surface roughness. If present, the upper limit of the heat treatment temperature is not limited to 500 ° C.

  The timing at which the gas that does not react with ZnTe starts to be introduced into the processing chamber 3 and the timing at which the inside of the processing chamber 3 starts to be heated may be reversed, or heating in the processing chamber 3 and introduction of gas. Can be performed simultaneously.

Next, the substrate 1 to be processed is transferred to a pedestal (not shown) in the processing chamber 3.
The inside of the processing chamber 3 is a normal pressure under a film forming temperature (500 ° C. or less in the first embodiment) in an atmosphere of a gas that does not react with ZnTe (nitrogen in the first embodiment). Alternatively, it is in a pressurized state (in this first embodiment, atmospheric pressure), and the substrate 1 to be processed is placed in the processing chamber 3 for a predetermined time.

  In addition, when the inside of the processing chamber 3 is in a reduced pressure state, ZnTe has a phenomenon in which atoms are evaporated and removed from the surface of the thin film. Therefore, the inside of the processing chamber 3 is preferably set to a normal pressure or a pressurized state. In addition, since it is difficult to handle the heat treatment apparatus 2 when the inside of the processing chamber 3 is in a high pressure state, it is more preferable that the inside of the processing chamber 3 is in a normal pressure state.

  Next, the function and effect of the p-type ZnTe thin film produced by the manufacturing method according to the first embodiment of the present invention will be described. Table 1 shows that the time for performing heat treatment on the substrate 1 to be processed (hereinafter referred to as heat treatment time) is constant at 30 minutes, the heat treatment temperature is set to no heat treatment, 300 ° C., 400 ° C. or 500 ° C., respectively. The result of measuring the carrier concentration, resistivity, and mobility of the p-type ZnTe thin film in the case where it carried out is shown.

Moreover, based on Table 1, the graph which shows the change of the electrical property of a p-type ZnTe thin film is shown in FIG. In FIG. 2, circles (◯) indicate carrier concentration values, triangles (Δ) indicate resistivity values, and squares (□) indicate mobility values.
Further, the substrate 1 to be processed was subjected to heat treatment with a constant heat treatment time of 30 minutes and a heat treatment temperature of 300 ° C., 400 ° C., 500 ° C., 600 ° C., 700 ° C. or 800 ° C. without heat treatment. FIG. 3 shows a graph showing the change of the photoluminescence spectrum measured at room temperature of the p-type ZnTe thin film in the case. In FIG. 3, in order to facilitate comparison of the photoluminescence intensity at each heat treatment temperature, the value of the photoluminescence intensity at each heat treatment temperature is translated along the vertical axis, and the photoluminescence intensity is calculated for each heat treatment temperature. The difference in temperature from the highest value to the lowest value was compared.

As shown in Table 1 and FIGS. 2 and 3, as the heat treatment temperature is increased, the carrier concentration and the photoluminescence intensity are remarkably increased. When the heat treatment temperature is higher than 500 ° C., the heat treatment temperature is 500 ° C. It can be seen that the photoluminescence intensity decreases with respect to the photoluminescence intensity. Specifically, in the conventional p-type ZnTe thin film without heat treatment, the carrier concentration is 1.87 × 10 ¹⁷ cm ⁻³ and the photoluminescence intensity at room temperature is 120, whereas the heat treatment at 500 ° C. is performed. In the p-type ZnTe thin film according to the present invention, the carrier concentration is 1.09 × 10 ¹⁸ cm ⁻³ , the photoluminescence intensity at room temperature is 1130, and the carrier concentration and the photoluminescence intensity are improved about 10 times. It was seen. Thus, if the heat treatment time is constant, the quality of the epitaxial film can be improved as the heat treatment temperature for the p-type ZnTe thin film is increased with the film formation temperature as the upper limit.

  Even if the heat treatment temperature is higher than the film formation temperature, the photoluminescence intensity can be improved as compared with the conventional p-type ZnTe thin film without heat treatment, but the constituent elements of the p-type ZnTe thin film 1b are In order to prevent evaporation and surface roughness, it is preferable to perform the heat treatment at a heat treatment temperature lower than the film formation temperature. In addition, it is more preferable to perform the heat treatment at substantially the same heat treatment temperature as the film formation temperature because the photoluminescence intensity that maximizes the difference from the highest value to the lowest value can be obtained when the heat treatment time is constant.

  As for the resistivity of the p-type ZnTe thin film, an increase in carrier concentration means an increase in the number of carriers that carry charges, and it is decreased by performing heat treatment. In addition, regarding the mobility of the p-type ZnTe thin film, the mobility usually decreases as the carrier concentration increases, but it can be seen that the mobility hardly changes.

  Next, with respect to the substrate 1 to be processed, the heat treatment temperature is kept constant at 420 ° C., and the heat treatment time is 0 minutes (no heat treatment), 10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 3 hours or 4 FIG. 4 shows a graph showing changes in the photoluminescence spectrum measured at room temperature of the p-type ZnTe thin film when heat treatment is performed as time. In FIG. 4, in order to facilitate the comparison of the photoluminescence intensity at each heat treatment time, the value of the photoluminescence intensity at each heat treatment time is translated along the vertical axis. As shown in FIG. 4, it can be seen that an emission band appears in the vicinity of a wavelength of 549 nm, and the photoluminescence intensity at room temperature of the p-type ZnTe thin film is improved as the heat treatment time is increased. Thus, the quality of the epitaxial film can be improved as the heat treatment time for the p-type ZnTe thin film is extended.

  In addition, the heat treatment temperature is kept constant at 420 ° C. for the substrate 1 to be treated, and the heat treatment time is 0 minutes (no heat treatment), 10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, or 4 hours. FIG. 5 shows a graph showing changes in the photoluminescence spectrum measured at 4.2 K (liquid helium temperature) of the p-type ZnTe thin film when heat treatment is performed. Moreover, the graph expanded about the wavelength range of 520-540 nm in FIG. 5 is shown in FIG. In FIGS. 5 and 6, in order to facilitate the comparison of the photoluminescence intensity at each heat treatment time, the value of the photoluminescence intensity at each heat treatment time is translated along the vertical axis. In FIGS. 5 and 6, DAP emission indicates donor-acceptor pair emission, FB emission indicates acceptor emission, and Ia emission indicates acceptor-bound exciton emission.

  The inventors of the present application considered the results of FIGS. 5 and 6 for the mechanism of the present invention in which the carrier concentration and the photoluminescence intensity were dramatically improved by the heat treatment process in the first embodiment of the present invention. I guessed as follows.

  As shown in FIGS. 5 and 6, when the heat treatment time is 0 minute (no heat treatment), DAP emission appears, and the donor and acceptor coexist in the p-type ZnTe thin film 1b. I understand.

  Here, Te is a group VI, phosphorus (P) is a group V, and when a group V phosphorus (P) enters a lattice position of a group VI Te, one electron is insufficient. ) Functions as an acceptor. In addition, the p-type ZnTe thin film 1b is laminated on the substrate 1a by spraying Zn and Te source gases onto the substrate 1a and reacting Zn and Te into a compound in the film forming process. However, there are cases where Zn and Te are displaced from the normal lattice position. In this case, when ZnTe is doped with phosphorus (P), phosphorus (P) does not enter the lattice position of the normal acceptor, so that phosphorus (P) functions as a donor as well as a lattice position that functions as an acceptor. It will enter the grid position. Thereby, the donor and the acceptor coexist in the p-type ZnTe thin film 1b, and DAP emission appears.

  Further, as shown in FIGS. 5 and 6, as the heat treatment time is increased, the position of DAP emission shifts to the short wavelength side, and when the heat treatment time is 1 hour, there is no DAP emission and FB emission occurs. Appears. This is because phosphorus (P) which is not arranged at the lattice position of the normal acceptor enters the lattice position of the normal acceptor by applying heat from the outside, and there is a donor in the p-type ZnTe thin film. This is because there is no longer an acceptor. As a result, there is an emission peak that appears at a regular lattice position.

  Therefore, in the conventional p-type ZnTe thin film without heat treatment, there is phosphorus (P) that is not arranged at the regular acceptor lattice position. Therefore, all phosphorus (P) in the p-type ZnTe thin film functions as an acceptor. However, by performing heat treatment, phosphorus (P) that is not arranged at the lattice position of the regular acceptor can be moved to the lattice position of the regular acceptor, and functions as an acceptor. It is considered that the number of phosphorus (P) could be increased as compared with the conventional p-type ZnTe thin film.

  As described above, in the first embodiment of the present invention, the carrier concentration and the photoluminescence intensity can be increased by performing heat treatment on the p-type ZnTe thin film. That is, increasing the carrier concentration decreases the series resistance, and increasing the photoluminescence intensity also decreases non-radiative recombination centers. Therefore, the light emission efficiency of the photoelectric conversion functional element using the p-type ZnTe thin film according to the first embodiment of the present invention can be improved.

(Second embodiment of the present invention)
FIG. 7 is a cross-sectional view for explaining a laminated structure of a semiconductor according to the second embodiment for carrying out the present invention, and FIG. 8 shows the concentration of aluminum impurities in the semiconductor according to the second embodiment for carrying out the present invention. It is a graph which shows distribution. 7, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and the description thereof is omitted.

  The second embodiment is different from the first embodiment only in that the ZnTe thin film is composed of a plurality of layers and performs the thermal diffusion treatment process. 1 has the same operational effects.

  In FIG. 7, the substrate 1 to be processed is formed by sequentially forming the first p-type ZnTe thin film 11a and the second p-type ZnTe thin film 11b on the ZnTe substrate 10 by the conventional film forming process described above. The heat treatment is performed in the heat treatment step.

The second p-type ZnTe thin film 11b has a lower hole concentration than the first p-type ZnTe thin film 11a, and the hole concentration X [cm ⁻³ ] of the first p-type ZnTe thin film 11a is , Consistent with the desired interfacial aluminum impurity concentration.

Next, the thermal diffusion treatment process in the second embodiment of the present invention will be described.
First, an Al thin film having a thickness of 10 nm or more is deposited on the surface of the substrate 1 to be processed shown in FIG. 7 by various thin film manufacturing methods such as vacuum evaporation or sputtering.
Next, the substrate 1 on which the Al thin film is deposited is placed in a processing chamber of an electric furnace, and an arbitrary time is taken at a temperature of 400 to 600 ° C. in an atmosphere of nitrogen, hydrogen, helium or argon. Perform thermal diffusion.

  Here, the thermal diffusion treatment temperature and time depend on the film thicknesses of the first p-type ZnTe thin film 11a and the second p-type ZnTe thin film 11b, and the hole concentration of the first p-type ZnTe thin film 11a, The conditions are set such that the aluminum impurity concentration at the interface between the first p-type ZnTe thin film 11a and the second p-type ZnTe thin film 11b after thermal diffusion exceeds the hole concentration of the first p-type ZnTe thin film 11a. There is a need to.

Next, an aluminum impurity concentration profile in the substrate 1 to be processed manufactured under such conditions is shown in FIG.
In the case of normal semiconductor silicon or the like, when the thermal diffusion of impurities is performed under the condition that the surface concentration is always constant, the depth distribution of the impurities is the complementary error function (erfc function) shown by the two-dot chain line in FIG. Will follow.

However, when thermal diffusion of aluminum impurities is performed on the substrate 1 having the structure shown in FIG. 7, the hole concentration X [cm] of the first p-type ZnTe thin film 11a is shown as shown by the solid line in FIG. ⁻³ ] and the depth Y at which the aluminum impurity concentration matches, a very steep aluminum impurity distribution can be formed. Note that the aluminum impurity concentration at the interface substantially matches the hole concentration X [cm ⁻³ ] of the first p-type ZnTe thin film 11a.

  The reason why such a steep aluminum impurity distribution can be formed is that the surface side of the substrate 1 to be processed is n-type because the aluminum impurity (donor) concentration is high at the depth Y, and the ZnTe substrate 10 side has holes. The concentration is p-type, and a pn junction diffusion potential is generated at this interface.

  It is presumed that Al atoms introduced into ZnTe by thermal diffusion are diffused in an ionic state, and the presence of a diffusion potential inhibits the diffusion of aluminum impurities. It is estimated that it becomes difficult to diffuse on the substrate 10 side, and a steep concentration distribution can be formed.

  In manufacturing an electronic device such as a light-emitting device, forming a structure having a steep interface is an important element that leads to high performance. The semiconductor manufacturing method in the second embodiment is an electronic device. It can be said that this is an extremely effective technique for improving the performance of devices.

  In the second embodiment, an example in which the thermal diffusion treatment process is performed using the substrate 1 to be processed made of p-type ZnTe having a three-layer structure (including the ZnTe substrate 10) is shown. The p-type ZnTe thin film 1b is not limited and may be any p-type ZnTe thin film 1b composed of a plurality of layers whose hole concentration decreases from the substrate 1a toward the surface. Impurities for diluting the hole concentration are added to the p-type ZnTe thin film 1b. By performing thermal diffusion from the surface, a steep concentration distribution can be formed.

  Further, if a thermal diffusion treatment process is performed on the substrate 1 to be processed on which the n-type ZnTe thin film 1b is formed, the n-type ZnTe thin film 1b has a plurality of electron concentrations that decrease from the substrate 1a toward the surface. A steep concentration distribution can be formed by forming a layer and thermally diffusing impurities for diluting the electron concentration from the surface into the n-type ZnTe thin film 1b.

  In the second embodiment, the thermal diffusion treatment process is performed on the substrate 1 to which the film formation process and the heat treatment process described above have been performed. The heat treatment process is also performed after the film formation process. By performing the thermal diffusion treatment step, the number of semiconductor manufacturing steps can be reduced, and the same effects as those of the first and second embodiments can be achieved.

  The thermal diffusion process that also serves as a heat treatment process is a process in which the p-type ZnTe thin film 1b formed on the substrate 1a in the film formation process described in the first embodiment has holes from the substrate 1a toward the surface. A plurality of layers with decreasing concentrations, a gas that does not react with zinc telluride in the heat treatment step described above in the first embodiment is nitrogen, hydrogen, helium, or argon, and a heat treatment temperature is 400 to 600 ° C. 1 is subjected to a heat treatment step. Before this heat treatment step, aluminum is deposited on the surface of the p-type ZnTe thin film 1b, so that aluminum impurities are removed from the surface of the p-type ZnTe thin film 1b in the heat treatment step. Thermal diffusion will occur.

It is a schematic block diagram which shows the heat processing apparatus used in 1st Embodiment for implementing this invention. It is a graph which shows the change of the electrical property of the ZnTe thin film by heat processing with fixed heat processing time. It is a room temperature photoluminescence characteristic figure which shows the change of the photoluminescence spectrum at room temperature of the ZnTe thin film by heat processing with fixed heat processing time. It is a room temperature photoluminescence characteristic figure which shows the change of the photoluminescence spectrum in the room temperature of the ZnTe thin film by heat processing with constant heat processing temperature. It is a photoluminescence characteristic figure which shows the change of the photoluminescence spectrum in 4.2K of the ZnTe thin film by heat processing with constant heat processing temperature. It is the characteristic view which expanded wavelength range 520-540 nm among the characteristic views shown in FIG. It is sectional drawing for demonstrating the laminated structure of a semiconductor in 2nd Embodiment for implementing this invention. It is a graph which shows concentration distribution of the aluminum impurity of the semiconductor in 2nd Embodiment for implementing this invention.

Explanation of symbols

1 Substrate
1a substrate
1b ZnTe thin film
2 Heat treatment equipment
3 treatment room
4 Electric furnace
5 Gas inlet
6 Exhaust port 10 ZnTe substrate 11a First p-type ZnTe thin film 11b Second p-type ZnTe thin film

Claims (3)

A film forming process for forming phosphorus-doped p- type zinc telluride on a substrate by metal organic vapor phase epitaxy ;
The substrate was deposited a zinc telluride of the p-type, in an atmosphere of a gas which does not react with the zinc telluride of the p-type, a heat treatment step of annealing,
Equipped with a,
The p-type zinc telluride thin film formed on the substrate in the film forming process step is composed of a plurality of layers in which the hole concentration decreases from the substrate toward the surface,
And a thermal diffusion treatment step of thermally diffusing the impurity for diluting the hole concentration from the surface of the p-type zinc telluride thin film . In the semiconductor manufacturing method according to claim 1,
A method for manufacturing a semiconductor, wherein a heat treatment temperature in the heat treatment step is equal to or lower than a film formation temperature in the film formation step.   In the manufacturing method of the semiconductor according to claim 1 or 2,
  A method for manufacturing a semiconductor, wherein the impurity is aluminum.

Images