JPH08130188A - Manufacture of p-type ii-vi compound semiconductor - Google Patents

Abstract

PURPOSE: To increase carrier concentration by thermally treating a II-VI compound semiconductor at a specific temperature in a gas atmosphere containing a group II or group VI element having a highest vapor pressure in group II and group VI elements without coating the surface of the II-VI compound semiconductor with a protective film. CONSTITUTION: A semi-insulating GaAS substrate 9 is heated up to a growth temperature in an H2 gas atmosphere by a susceptor 7 in a reaction tube 6 for an organometallic chemical vapor growth device. The inside of the reaction tube 6 is supplied with DM (dimethyl) Zn, DMSe and Di-PNH (P-type dopant), and a N-doped ZnSe layer is grown on the substrate 8 in an epitaxial manner. A ZnSe:N layer is heated at 650-750 deg.C while the reaction tube 6 is supplied with DMSe containing Se having a vapor pressure higher than Zn with the ZnSe:N-layered substrate 8 left on the susceptor 7 for the reaction tube 6, that is, without forming a protective film, and annealed in a short time. Accordingly, carrier concentration can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a p-type II-VI group compound semiconductor.

[0002]

2. Description of the Related Art In recent years, in order to improve the recording density of optical discs and the resolution of laser printers, there is an increasing demand for semiconductor lasers capable of emitting light at short wavelengths, and research aimed at realizing them has been made. It is active.

A II-VI group compound semiconductor is promising as a material used for producing a semiconductor laser capable of emitting light at such a short wavelength. In particular, the ZnMgSSe-based compound semiconductor, which is a quaternary II-VI group compound semiconductor, is
It is known to be suitable as a material for a clad layer or an optical waveguide layer when a blue or green light emitting semiconductor laser having a wavelength of 400 to 550 nm is formed on a GaAs substrate (for example, Electron. Lett. 28, 1798). (1992)).

Until now, the growth of II-VI group compound semiconductors has been carried out exclusively by the molecular beam epitaxy (MBE) method, but this MBE method is unsatisfactory in terms of productivity. Therefore, in recent years, an attempt has been made to apply a metal organic chemical vapor deposition (MOCVD) method, which has excellent productivity and is widely used as a method for growing a III-V group compound semiconductor, to the growth of a II-VI group compound semiconductor. .

Conventionally, the p-type II-VI formed by the MOCVD method is used.
Group compound semiconductors are grown as follows.
For example, when p-type ZnSe is grown, dimethylzinc (DMZn) is used as a raw material of Zn which is a group II element,
Organometallic compounds such as diethyl zinc (DEZn), VI
Dimethyl selenium (DMS) as a raw material of Se, which is a group element
e), an organometallic compound such as diethyl selenium (DEZn) or a hydrogen compound such as hydrogen selenide (H ₂ Se), and a compound such as ammonia (NH ₃ ) as a p-type dopant containing nitrogen (N) serving as an acceptor impurity. Used. And, these Zn raw material, Se raw material and p
Type dopants are simultaneously supplied into the reaction tube in a gaseous state,
The p-type ZnSe is grown on the substrate which is placed in advance on the susceptor installed in the reaction tube and heated to a predetermined temperature.

However, when NH ₃ or the like is used as the p-type dopant as described above, the N in the grown crystal is increased.
It is difficult to obtain p-type ZnSe having a sufficiently high carrier concentration (hole concentration) because the doping efficiency of N is extremely low because it is difficult to be captured.

Therefore, in order to increase the N doping efficiency and grow p-type ZnSe having a higher carrier concentration,
A large amount of NH ₃ or the like used as a p-type dopant is supplied (J. Crystal Growth 101, 305 (1990)), or cracking is performed to efficiently generate radicals N from N contained in the p-type dopant. Radical N can be supplied using a plasma source (Appl. Phys. Lett. 63 (1
7), 2384 (1993)), and low-temperature growth using light irradiation is performed to prevent desorption of N from the surface of the grown crystal (Optical Volume No. 22, No. 11, page 688 ( 1993 1
January)). In addition, since N activation efficiency is low in N-doped ZnSe grown using NH ₃ as a p-type dopant, RTA (Ra
pid Thermal Annealing), that is, N is activated by short-time annealing (Appl. Phys. Le
tt. 62 (3), 270 (1993)).

[0008]

However, in the above-mentioned conventional method, at present, the effective acceptor concentration N _A −
N _D (N _A: acceptor concentration, N _D: donor concentration).. P-type ZnSe at (2~3) × 10 ¹⁶ cm ^-3 as low carrier concentration is not only obtained (Appl Phys Lett.62
(3), 270 (1993)). Further, in the method of performing cracking to efficiently generate the radical N or supplying the radical N by using a plasma source, a by-product is produced by a reaction with a raw material of a group II element or a raw material of a group VI element. There is a problem that (adduct) is formed, or radical N reacts with hydrogen (H ₂ ) which is a carrier gas of the MOCVD apparatus to form NH ₃ . Further, the low temperature growth method using light irradiation to prevent desorption of N from the surface of the grown crystal is a II-VI group compound semiconductor containing Mg such as ZnMgSSe, which requires a higher growth temperature than ZnSe. It is impossible to apply to the growth of.

As described above, it has been difficult to obtain a p-type II-VI group compound semiconductor having a sufficiently high carrier concentration. However, it is a semiconductor laser or a light emitting diode using the II-VI group compound semiconductor. Since this is a great obstacle in manufacturing a semiconductor light emitting device, the improvement thereof has been desired.

Therefore, an object of the present invention is to produce a p-type II-VI group compound semiconductor having a sufficiently high carrier concentration, and to prevent evaporation of its constituent elements and surface roughness. It is to provide a method for manufacturing a p-type II-VI compound semiconductor.

[0011]

In order to achieve the above object, a method for producing a p-type II-VI group compound semiconductor according to the present invention comprises a raw material of a II group element, a raw material of a VI group element, and at least one of II-VI doped with nitrogen atoms by a vapor phase growth method using a p-type dopant comprising an organic compound containing a nitrogen atom and at least two groups having a molecular weight of at least 12 are bonded to the nitrogen atom
A group compound semiconductor is grown, and after or during the growth,
At least a group II element or a group VI element having the highest vapor pressure among the group II element and the group VI element constituting the group II-VI compound semiconductor without covering the surface of the group II-VI compound semiconductor with the protective film is used. It is characterized in that the heat treatment of the II-VI group compound semiconductor is performed at a temperature of 650 to 850 ° C. in a gas atmosphere containing the same.

In the present invention, in order to produce a p-type II-VI group compound semiconductor having a higher carrier concentration,
The heat treatment is preferably performed at a temperature of 650 to 750 ° C.

In the present invention, the heat treatment is typically performed in a reaction tube of a vapor phase growth apparatus used for growing II-VI compound semiconductors. This heat treatment is performed by, for example, resistance heating, high frequency induction heating, or short-time heating by lamp light.

In the present invention, the molecular weight of at least two groups bonded to the nitrogen atom in the organic compound as the p-type dopant is about 500 ° C. which is a general growth temperature of II-VI group compound semiconductors. In order for these groups to be easily thermally decomposed and liberated from the nitrogen atom, it is preferably selected larger than 36. Further, in order to thermally decompose these groups with the same probability to liberate them from the nitrogen atom, those groups having the same molecular weight are preferably used.

In the present invention, the organic compound as the p-type dopant typically contains one nitrogen atom,
An organic compound in which two hydrogen atoms having a molecular weight of more than 36 and one hydrogen atom are bonded to the nitrogen atom, and three nitrogen atoms having a molecular weight of more than 36 are bonded to the nitrogen atom. There are organic compounds. Examples of the former organic compound include the following (a) to (f), and examples of the latter organic compound include the following (g) to (r).
Is mentioned.

(A) Diisopropylamine (Di-PN
H)

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(B) Dipropylamine (D-PNH)

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(C) Dibutylamine (D-BNH)

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(D) Diisobutylamine (Di-BN
H)

[Chemical 4]

(E) Di-tert-butylamine (Ds-BN
H)

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(F) Ditertiarybutylamine (Dt-
BNH)

[Chemical 6]

(G) Tripropylamine (T-PN)

[Chemical 7]

(H) Triisopropylamine (Ti-P
N)

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(I) Tributylamine (T-BN)

[Chemical 9]

(J) Triisobutylamine (Ti-B
N)

[Chemical 10]

(K) Tri-tert-butylamine (Ts-B
N)

[Chemical 11]

(L) Tritertiarybutylamine (Tt
-BN)

[Chemical 12]

(M) Diisopropylmethylamine (Di
-PMN)

[Chemical 13]

(N) Dipropylmethylamine (D-PM
N)

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(O) Dibutylmethylamine (D-BM
N)

[Chemical 15]

(P) Diisobutylmethylamine (Di-
BMN)

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(Q) Di-tert-butylmethylamine (Ds-
BMN)

[Chemical 17]

(R) Ditertiarybutylmethylamine (Dt-BMN)

Embedded image

In the organic compounds (a) to (r) listed above, two or three groups are bonded to the N atom, and the number of H atoms directly bonded to the N atom is one. It is the following. This is because ammonia (NH ₃ ) and tertiary butylamine (t
In —BNH ₂ ), one or less groups are bonded to the N atom, and the number of H atoms directly bonded to the N atom is different from two or three.

In a preferred embodiment of the present invention,
Nitrogen atoms are delta-doped (δ-doped) on the surface of the group II element of the group II-VI compound semiconductor. Further, instead of this delta dope, a flow modulation method that can obtain the same effect as this delta dope may be used. Specifically, in this flow modulation method, the supply of the group II element raw material and the supply of the p-type dopant are maintained, and the growth is interrupted by interrupting the supply of the group VI element raw material.

In the present invention, the vapor phase growth method is as follows:
In addition to the MOCVD method, the MBE method using a gas source can be used.

The II produced in the present invention
The group-VI compound semiconductor comprises at least one group II element selected from the group consisting of Zn, Mg, Cd, Hg and Be and at least one group VI element selected from the group consisting of Se, S and Te. II-VI configured
It is a group compound semiconductor. Specific examples of the II-VI group compound semiconductor include ZnSe, ZnSSe, and ZnMg.
For example, SSe.

[0038]

The p-type I according to the present invention constructed as described above
According to the method for producing a group I-VI compound semiconductor, the p-type dopant used for vapor phase growth contains at least one nitrogen atom, and at least two groups having a molecular weight of at least 12 are bonded to the nitrogen atom. since an organic compound and is, there are those after the group is released from the pyrolysis to the nitrogen atom of the nitrogen atom thereof at least two bonds (dangling bonds), as in the prior art, such as NH ₃ The number of bonds of the nitrogen atom after thermal decomposition is at least one higher than that when it is used as a p-type dopant. For this reason, the nitrogen atoms are more likely to be bonded and taken in by the atoms on the surface of the grown crystal, and thus the grown II-V
The doping efficiency of nitrogen atoms to the group I compound semiconductor can be increased. Accordingly, II-V having a sufficiently high doping concentration of nitrogen atoms as acceptor impurities
It is possible to grow a group I compound semiconductor.

Since the heat treatment is performed at a temperature of 650 to 850 ° C. after or during the growth of the II-VI group compound semiconductor, nitrogen as an acceptor impurity is included in the II-VI group compound semiconductor during the growth. The bond between the hydrogen atom and the nitrogen atom taken in together with the atom can be broken to release this hydrogen atom as a hydrogen molecule to the outside. Therefore, inactivation of nitrogen atoms in the II-VI group compound semiconductor by hydrogen atoms can be prevented, and the activation rate of nitrogen atoms can be increased. Further, during this heat treatment, the surface of the II-VI group compound semiconductor is not covered with the protective film, but I constituting the II-VI group compound semiconductor is formed.
I having the highest vapor pressure of group I and group VI elements
By performing this heat treatment in a gas atmosphere containing at least a Group I element or a Group VI element, it is possible to prevent the constituent elements of the II-VI group compound semiconductor from evaporating or the surface to be roughened during this heat treatment. Can be prevented.

From the above, p with a sufficiently high carrier concentration
It is possible to manufacture a type II-VI group compound semiconductor and prevent evaporation of the constituent elements and surface roughness.

Furthermore, in particular, when an organic compound containing one nitrogen atom and three groups having a molecular weight of more than 36 bonded to the nitrogen atom is used as a p-type dopant, the nitrogen atom is Since the hydrogen atom is not directly bonded, the nitrogen atom is not solely bonded to the hydrogen atom but is generated alone after the thermal decomposition. Therefore, the problem that hydrogen atoms contained in the p-type dopant are taken into the grown crystal and the hydrogen atoms inactivate nitrogen atoms as acceptor impurities can be almost completely solved. As a result, the p-type I having a higher carrier concentration is obtained.
A Group I-VI compound semiconductor can be obtained.

Further, the efficiency of incorporation of nitrogen atoms into the grown crystal is further increased by delta-doping nitrogen atoms on the surface of the group II element of the II-VI compound semiconductor or by using the flow modulation method. It is possible to obtain a p-type II-VI group compound semiconductor having a higher carrier concentration.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. First, the MOCVD apparatus used in the first embodiment of the present invention will be described. FIG. 1 shows the structure of the MOCVD apparatus.

As shown in FIG. 1, in this MOCVD apparatus, H ₂ gas highly purified by the H ₂ purifying apparatus 1 is supplied as a carrier gas into the bubblers 2, 3 and 4. Considering now the case of growing p-type ZnSe,
In each of these bubblers 2, 3, and 4, for example, Z
Dimethyl zinc (DMZn) as an n source, dimethyl selenium (DMSe) as an Se source, and Di-PNH as a p-type dopant are added. Then, by supplying the H ₂ gas into these bubblers 2, 3, 4, the source gas corresponding to the vapor pressure is supplied from each of these bubblers 2, 3, 4 together with H ₂ gas as a carrier gas. Is supplied into the reaction tube 6 through the reaction tube line 5. A susceptor 7 is installed in the reaction tube 6, and a substrate 8 is placed thereon.

Reference numeral 9 indicates a vent line. in this case,
Switching between the reaction tube line 5 of the source gas generated from the bubbler 2 and the vent line 9 can be performed by opening / closing the valves V ₁ and V ₂ , and the reaction tube line of the source gas generated from the bubbler 3 5 and the vent line 9 can be switched by opening and closing the valves V ₃ and V ₄ , and the dopant gas generated from the bubbler 4 can be switched between the reaction tube line 5 and the vent line 9. Valve V
₅ , V ₆ can be opened and closed. Note that reference numerals 10 to 14 denote mass flow controllers for controlling the flow rate of the H ₂ gas supplied from the H ₂ purifying device 1.

FIG. 2 shows a p-type Z according to the first embodiment of the present invention.
It is a sequence diagram which shows the state of supply of the source gas and the dopant gas in the growth method of nSe.

In the first embodiment, first, a semi-insulating GaAs substrate 21 (FIG. 3) is placed as the substrate 8 on the susceptor 7 in the reaction tube 6 of the MOCVD apparatus shown in FIG.
This semi-insulating GaAs substrate 21 is heated to H by the susceptor 7.
_{It is} heated to a growth temperature, for example, 450 ° C. in a ₂ gas atmosphere.

Next, DM as a Zn raw material is placed in the reaction tube 6.
All of ZnSe, DMSe as a raw material, and Di-PNH as a p-type dopant are simultaneously supplied (FIG. 2). As a result, as shown in FIG.
A ZnSe layer doped with N is formed on the As substrate 21 (“ZnSe:
Write "N layer". ) 22 is epitaxially grown.

Next, the semi-insulating GaAs substrate 21 on which the ZnSe: N layer 22 is epitaxially grown is MOCV.
While being placed on the susceptor 7 in the reaction tube 6 of the D device, DMSe containing Se, which has a higher vapor pressure than Zn, is supplied into the reaction tube 6 at a flow rate of 137 μmol / min or more, for example, ZnSe: The N layer 22 is heated and RTA, that is, short-time annealing is performed.

An example of the temperature sequence of this epitaxial growth and annealing is shown in FIG. As shown in FIG.
In this case, the temperature is raised from room temperature to 450 ° C at a constant rate, and
After epitaxially growing the ZnSe: N layer 22 at 50 ° C., the temperature is raised from 450 ° C. to 700 ° C. at a constant rate. Then, the temperature is maintained at 700 ° C. for 10 seconds and ZnSe: N
After RTA of layer 22, heating is stopped and cooled to room temperature.

FIG. 5 shows the photoluminescence spectrum of the ZnSe: N layer 22 which has been epitaxially grown and then annealed as described above, at 4.2 K (liquid helium temperature) before and after annealing, and the donor before annealing is measured. -Acceptor pair (DAP) emission (wavelength 4
Intensity of DAP emission after annealing with respect to the intensity I _DAPbefore of used emission) that observed near 60 nm I _DAPafter ratio I
_DAPafter / I _Intensity I of deep emission (emission due to deep energy level) before _DAPbefore and annealing
_Intensity of deep emission after annealing for DEEP _before I
_The result of measuring the annealing temperature dependency of _DEEPafter ratio I _DEEPafter / I _DEEPbefore is shown.

From FIG. 5, it can be seen that I _DAPafter / I _DAPbefore is maximum when the annealing temperature is around 700 ° C., and the maximum value is about 50. That is, 700 ° C
It can be seen that by performing RTA of the ZnSe: N layer 22 for 10 seconds, the intensity of DAP emission increases about 50 times. This DAP emission is evidence that N is doped, and the higher the intensity is, the larger the N doping amount is. Therefore, it is considered that the ZnSe: N layer 22 manufactured according to the first embodiment is doped with a large amount of N. Also, at this time, I _DEEPafter /
I _DEEPbefore is as small as 2-3, which means ZnS
It can be seen that the increase in the intensity of deep light emission after performing the RTA of the e: N layer 22 is small.

FIG. 6 shows the results of measuring the photoluminescence spectrum of the ZnSe: N layer 22 produced by the method according to the first embodiment at 4.2 K, which compares the intensity of DAP emission before and after annealing. is there. However, the growth temperature is 450 ° C and the pressure in the reaction tube 6 is 650T.
orr, DMZn as a Zn raw material, DMSe as a Se raw material, and Di-PNH as a p-type dopant are supplied at 5 μmol / min, 10 μmol / min and 141 μmol / min, respectively, and the thickness of the ZnSe: N layer 22 is about 2 μm. Is.

As is clear from FIG. 6, the wavelength is 460 nm.
The DAP light emission observed in the vicinity was observed as a single group of very broad DAP light emission after the annealing although it was observed separately before the annealing. It is considered that this is caused by the activation of N in the ZnSe: N layer 22 by annealing.

In FIG. 6, peaks other than DAP emission are I ₁ (neutral acceptor bound excitons) emission, DA
Examples include phonon replica of P emission, Y emission (emission due to misfit dislocation, etc.).

FIG. 7 shows the flow rate of DMSe supplied into the reaction tube 6 of the MOCVD apparatus during annealing and DA before annealing.
P emission intensity I DAP after annealing for DAP _before
The relationship between the emission intensity I _DAPafter ratio I _DAPafter / I _DAPbefore is shown. As is clear from FIG. 7, DMSe
I _DAPafter / I _DAPbefore monotonically increases as the flow rate of the ZnSe: N layer 22 increases.
The flow of DMSe during annealing of ZnSe: N layer 2
It can be seen that it is effective in preventing the desorption of Se in 2.

Further, when the morphology of the surface of the ZnSe: N layer 22 of the sample annealed by changing the flow rate of DMSe was observed by an optical microscope, the ZnSe: N layer 2
It was found that the surface roughness does not occur if DMSe is supplied at about 137 μmol / min or more during the annealing of 2.

Next, although not shown, a circular Au film is formed on the ZnSe: N layer 22 manufactured according to the first embodiment.
An electrode and an Au electrode surrounding the electrode are formed, and a negative bias voltage and a positive bias voltage are applied to the circular Au electrode and the surrounding Au electrode, respectively, to perform capacitance (C) -voltage (V) measurement. It was And this C-V
From the measurement result, the relative dielectric constant of ZnSe is set to 9.3,
ZnSe: Results of estimation of N _A -N _D from the surface in the depth direction of the N layer 22, before annealing N _A -N _D was the value of the unmeasurable region of 1 × 10 ¹⁶ cm ^-3 or less annealing It was later found that N _A −N _D increased to 1 × 10 ¹⁷ cm ⁻³ . This level of N _A -N _D is sufficient for manufacturing a semiconductor light emitting device such as a semiconductor laser.

As described above, according to the first embodiment,
Since the growth is performed using Di-PNH as the p-type dopant, the ZnSe: N layer 22 doped with N at a high concentration can be grown. The reason why the ZnSe: N layer 22 having a high N concentration can be grown is that N generated by thermal decomposition of Di-PNH at the time of growth.
This is because the atom has two bonds, so that the incorporation efficiency of N into the ZnSe crystal is high, and thus the doping efficiency of N is high. Further, after the ZnSe: N layer 22 having a high N concentration is grown in this manner, annealing is performed at a temperature of, for example, about 700 ° C., so that H that has been taken into the ZnSe crystal together with N atoms is grown.
The bond between the atom and the N atom can be broken, and the H atom can be released as H ₂ to the outside. Therefore, ZnSe:
Inactivation of N atoms in the N layer 22 by H atoms can be prevented. With these, the ZnSe: N layer 22 having a sufficiently high carrier concentration of about 1 × 10 ¹⁷ cm ⁻³ , that is, the p-type ZnSe layer can be produced.

Further, in order to prevent the constituent elements of the ZnSe: N layer 22 from being detached from the ZnSe: N layer 22 at the time of annealing, and the surface of the ZnSe: N layer 22 to be roughened, the surface of the ZnSe: N layer 22 is covered with a protective film prior to annealing. It is possible that
According to the first embodiment, during the annealing, DMSe, which is a compound of Se having a higher vapor pressure than Zn, is supplied into the reaction tube 6 of the MOCVD apparatus.
Even if the surface of the N layer 22 is not covered with the protective film, the same effect as when the protective film is formed can be obtained. Therefore, the labor required for forming and removing this protective film can be omitted, and the productivity can be improved. Moreover, in order to form the protective film, after the epitaxial growth is completed, the sample is once taken out from the reaction tube 6 of the MOCVD apparatus, and then the vacuum deposition apparatus, the sputtering apparatus, the C
Since it is necessary to transfer it to a VD device or the like and form a protective film there, there is a possibility that the surface of the sample, contamination or damage may occur at that time, but in the first embodiment there is no such problem. .

Next, a second embodiment of the present invention will be described. In the second embodiment, N is doped by the flow modulation method that can obtain substantially the same effect as δ doping.

FIG. 8 shows a p-type Z according to the second embodiment of the present invention.
It is a sequence diagram which shows the state of supply of the source gas and the dopant gas in the growth method of nSe. In addition, FIG.
A to E are t = t ₁ , t ₂ , t ₃ , t _{4 in FIG} .
The state of the growth layer at each time t ₅ is shown.

Hereinafter, with reference to FIGS. 1, 8 and 9,
A method of manufacturing p-type ZnSe according to the second embodiment will be described.

First, a semi-insulating GaAs substrate 21 is placed as a substrate 8 on the susceptor 7 in the reaction tube 6 of the MOCVD apparatus shown in FIG. 1, and the semi-insulating GaAs substrate 21 is placed in the H ₂ gas atmosphere by the susceptor 7. At a growth temperature, for example 45
Heat to 0 ° C.

Next, DM as a Zn raw material is placed in the reaction tube 6.
By supplying ZnSe, DMSe as a raw material, and Di-PNH as a p-type dopant at the same time, a ZnSe: N layer 23 is epitaxially grown on the semi-insulating GaAs substrate 21, as shown in FIG. 9A. This ZnSe: N layer 23 is grown epitaxially at time t.
= 0 to time t = t ₁ (FIG. 8). The ZnSe: N layer 23 epitaxially grown first serves as a buffer layer for the ZnSe: N layer grown thereafter.

Next, at time t = t ₁ , the supply of DMSe is stopped while the supply of DMZn and Di-PNH is maintained, and the growth is stopped. This growth interruption occurs at time t =
Perform until t ₂ . During this growth interruption, ZnZn is adsorbed on the surface of the ZnSe: N layer 22 as a buffer layer due to thermal decomposition of DMZn supplied into the reaction tube 6, and the surface is covered with the Zn adsorbed layer. Zn in Zn adsorption layer
N having two bonding hands, which is generated by thermal decomposition of Di-PNH, is adsorbed on the carbon dioxide, and N is taken into the growth layer. In FIG. 9B, this Zn and N adsorption layer is indicated by reference numeral 24.

FIG. 10 shows a state in which an N atom having two bonds produced by thermal decomposition of Di-PNH is bonded to the plane of Zn which is a group II element of ZnSe crystal. As shown in FIG. 10, in this case, the N atom is bound to two Zn atoms on the plane of Zn by two bonds, so that the bonding force between the Zn atom and the N atom is strong, Desorption of N atom is unlikely to occur. In addition, N atoms are bonded while directly reflecting the crystal structure of ZnSe.

Next, at time t = t ₂ , the supply of DMSe into the reaction tube 6 is restarted, and this D is maintained until time t = t _3.
Continue to supply MSe. As a result, all of DMZn, DMSe and Di-PNH are simultaneously supplied into the reaction tube 6, and the ZnSe: N layer 22 is thinly epitaxially grown as shown in FIG. 9C.

Next, at time t = t ₃ , DM
DMSe while maintaining the supply of Zn and Di-PNH
Supply is suspended and growth is suspended. During this growth interruption, as shown in FIG. 9D, an adsorption layer 24 of Zn and N is formed on the surface of the ZnSe: N layer 22.

Next, at time t = t ₄ , the supply of DMSe into the reaction tube 6 is restarted, and this D is maintained until time t = t _5.
Continue to supply MSe. As a result, all of DMZn, DMSe and Di-PNH are simultaneously supplied into the reaction tube 6, and again the ZnSe: N layer 2 is formed as shown in FIG. 9E.
2 is thinly epitaxially grown.

In this way, the growth is suspended to form the adsorption layer 25 of Zn and N, and the step of thinly epitaxially growing the ZnSe: N layer 22 thereon is repeated a necessary number of times to obtain the required total thickness. With ZnS
The e: N layer 22 is epitaxially grown.

Next, similarly to the first embodiment, while supplying DMSe into the reaction tube 6 of the MOCVD apparatus, for example, 700
RTA of the ZnSe: N layer 22 is performed under the conditions of ° C and 10 seconds.

As described above, according to the second embodiment,
Not only is Di-PNH used as a p-type dopant, but DMZn serving as a Zn source, DMSe serving as a Se source, and Di-PNH serving as a p-type dopant are simultaneously supplied to grow the ZnSe: N layer 22. Since the step of performing and the step of forming the adsorption layer 25 of N and Zn by interrupting the growth of DMSe while interrupting the supply of DMZn and the supply of Di-PNH are alternately repeated. , N to ZnSe
The efficiency of uptake of N
ZnSe: N layer 2 of a required thickness heavily doped with
2 growths can be performed. And after this this Z
By annealing the nSe: N layer 22 at a temperature of, for example, about 700 ° C., the bond between the H atom and the N atom taken together with the N atom in the ZnSe crystal during the growth is cut and the H atom is converted into the H atom. ₂ can be released to the outside, and thus the inactivation of N atoms in the ZnSe: N layer 22 by H atoms can be prevented. Due to these facts, the carrier concentration is higher than that of the first embodiment.
The nSe: N layer 22, that is, the p-type ZnSe layer can be formed. Moreover, the atmosphere during this annealing is DM
Since the gas atmosphere contains Se, the ZnSe: N layer 22
Even if the surface of the is not covered with a protective film, it is possible to prevent evaporation of the constituent elements and surface roughness.

Next, a third embodiment in which the present invention is applied to manufacture of a semiconductor laser using a II-VI group compound semiconductor will be described. The semiconductor laser manufactured by the third embodiment is a so-called SCH (Separate Confineme).
nt Heterostructure) structure.

11 and 12 show a semiconductor laser manufactured according to this third embodiment. Here, FIG.
Is a cross-sectional view perpendicular to the cavity length direction of this semiconductor laser,
FIG. 12 shows a sectional view parallel to the cavity length direction of this semiconductor laser.

As shown in FIGS. 11 and 12, in the method of manufacturing the semiconductor laser according to the third embodiment,
First, the MOCVD method including the step of interrupting the growth by the flow modulation method similar to that of the above-described second embodiment on the n-type GaAs substrate 41 having a (100) plane orientation doped with, for example, silicon (Si) as a donor impurity. Thus, the n-type ZnSe buffer layer 42 doped with, for example, iodine (I) as a donor impurity, and the n-type Zn _1-p Mg _p S _q Se doped with, for example, I as a donor impurity.
_1-q cladding layer 43, n-type ZnS _u Se _1-u optical waveguide layer 44 doped with, for example, I as a donor impurity, active layer 45 formed of, for example, an intrinsic (i-type) Zn _1-z Cd _z Se quantum well layer , P-type ZnS _u Se _1-u optical waveguide layer 46 doped with N as an acceptor impurity, and p-type Zn _1-p Mg _p doped with N as an acceptor impurity.
An S _q Se _1-q clad layer 47, a p-type ZnS _v Se _1-v layer 48 doped with N as an acceptor impurity,
For example, p-type Z doped with N as an acceptor impurity
An nSe contact layer 49, a p-type Z in which a quantum well layer made of p-type ZnTe doped with N as an acceptor impurity and a barrier layer made of p-type ZnSe are alternately stacked.
nSe / ZnTe multiple quantum well (MQW) layer 50 and p-type Z doped with N as an acceptor impurity, for example.
The nTe contact layer 51 is sequentially epitaxially grown. The p-type ZnSe / ZnTe MQW layer 50 will be described in detail later.

In this case, in the epitaxial growth of the n-type ZnSe buffer layer 42, for example, DMZn is used as a Zn raw material, DMSe is used as the Se raw material, and ethyl iodide is used as a dopant for I. n-type Zn _1-p Mg _p
In the epitaxial growth of the S _q Se _1-q cladding layer 43, for example, DMZn as a Zn raw material, bismethylcyclopentadienyl magnesium ((MeCp) ₂ Mg) as a Mg raw material, diethyl sulfur (DES) as an S raw material, and Se raw material. As DMSe and ethyl iodide as a dopant for I. n-type ZnS _u Se
_In the epitaxial growth of the _1-u optical waveguide layer 44, for example, DMZn as a Zn raw material, DES as an S raw material,
DMSe is used as the Se raw material and ethyl iodide is used as the I dopant. In addition, i-type Zn _1-z Cd _z Se
In the epitaxial growth of the active layer 45 formed of a quantum well layer, for example, DMZn is used as a Zn raw material, dimethylcadmium (DMCd) is used as a Cd raw material, and DMSe is used as a Se raw material.

On the other hand, p-type ZnS _u Se _1-u optical waveguide layer 46
In the epitaxial growth of the p-type ZnS _v Se _1-v layer 48, DMZn is used as a Zn raw material, H ₂ S is used as an S raw material, DMSe is used as a Se raw material, and Di-PNH is used as a dopant for N. In addition, p-type Zn
_In the epitaxial growth of the _1-p Mg _p S _q Se _1-q cladding layer 47, for example, DMZn as a Zn raw material,
(MeCp) ₂ Mg as Mg raw material and DE as S raw material
DMSe is used as the S and Se raw materials and Di-PNH is used as the N dopant. p-type ZnSe contact layer 4
9 and p-type Z of p-type ZnSe / ZnTe MQW layer 50
In the epitaxial growth of the nSe layer, for example, Z
DMZn is used as the n source, DMSe is used as the Se source, and Di-PNH is used as the N dopant. further,
In epitaxial growth of the p-type ZnTe layer of the p-type ZnSe / ZnTe MQW layer 50 and the p-type ZnTe contact layer 51, for example, DMZn, T
e Diethyl tellurium (DETe) is used as a raw material and Di-PNH is used as a dopant for N.

Further, in the epitaxial growth of the n-type ZnSe buffer layer 42, the step of growing while simultaneously supplying DMZn, DMSe and ethyl iodide, and, for example, interrupting the supply of DMSe while maintaining the supply of DMZn and ethyl iodide And the step of interrupting the growth is repeated. In addition, n-type Zn _1-p Mg _p
In the epitaxial growth of the S _q Se _1-q cladding layer 43, DMZn, (MeCp) ₂ Mg, DES, DM
A step of growing while simultaneously supplying Se and ethyl iodide, and, for example, DES and DMS while maintaining the supply of DMZn, (MeCp) ₂ Mg and ethyl iodide.
The step of interrupting the growth by interrupting the supply of e is repeated. In the epitaxial growth of the n-type ZnS _u Se _1-u optical waveguide layer 44, DMZn, DES, DM
The step of growing while simultaneously supplying Se and ethyl iodide and the step of interrupting the growth by interrupting the supply of DES and DMSe while maintaining the supply of DMZn and ethyl iodide are repeated.

Further, the p-type ZnS _u Se _1-u optical waveguide layer 4
6 and p-type ZnS _v Se _1-v layer 48 were grown epitaxially by DMZn, DES, DMSe and D
a step of growing while simultaneously supplying i-PNH;
DES while maintaining the supply of MZn and Di-PNH
And the step of interrupting the growth by interrupting the supply of DMSe is repeated. In addition, p-type Zn _1-p Mg _p
In the epitaxial growth of the S _q Se _1-q cladding layer 47, DMZn, (MeCp) ₂ Mg, DES, DM
A step of growing while simultaneously supplying Se and Di-PNH, and DMZn, (MeCp) ₂ Mg and Di-
The process of interrupting the growth by interrupting the supply of DES and DMSe while maintaining the supply of PNH is repeated. p-type ZnSe contact layer 49 and p-type Zn
In the epitaxial growth of the p-type ZnSe layer of the Se / ZnTe MQW layer 50, DMZn, DMSe and D
a step of growing while simultaneously supplying i-PNH;
DMS while maintaining the supply of MZn and Di-PNH
The step of interrupting the growth by interrupting the supply of e is repeated. In addition, in the epitaxial growth of the p-type ZnTe layer of the p-type ZnSe / ZnTe MQW layer 50 and the p-type ZnTe contact layer 51, DMZn, DE
The step of growing while simultaneously supplying Te and Di-PNH and the step of interrupting growth by interrupting the supply of DETe while maintaining the supply of DMZn and Di-PNH are repeated.

Next, the n-type GaAs substrate 41 on which the above layers are epitaxially grown is used as the reaction tube 6 of the MOCVD apparatus.
While being placed on the susceptor 7 inside, while supplying a compound of an element having a high vapor pressure among the elements constituting these layers, such as DMSe or DES, into the reaction tube 6,
For example, RTA is performed at a temperature of about 700 ° C.

Next, after forming a stripe-shaped resist pattern (not shown) having a predetermined width on the p-type ZnTe contact layer 51, the p-type ZnS _v Se _1-v layer 48 is formed using this resist pattern as a mask. Etching is performed up to a middle depth in the thickness direction by, for example, a wet etching method. As a result, the upper layer of the p-type ZnS _v Se _1-v layer 48, the p-type ZnSe contact layer 49, and the p-type ZnSe / Z are formed.
nTe MQW layer 50 and p-type ZnTe contact layer 5
1 is patterned into a stripe shape. The width of this stripe portion is, for example, 5 μm.

Next, an alumina (Al ₂ O ₃ ) film having a thickness of 300 nm, for example, is formed on the entire surface by a vacuum deposition method while leaving the resist pattern used for the above etching, and the resist pattern is formed on the alumina (Al ₂ O ₃ ) film. Al ₂ formed
It is removed together with the O ₃ film (lift-off). As a result, p-type ZnS _v Se in the portion other than the above-mentioned stripe portion is
_An insulating layer 52 made of an Al ₂ O ₃ film is formed only on the _1-v layer 38.

Next, the stripe-shaped p-type ZnTe contact layer 51 and the insulating layer 52 have a thickness of, for example, 1 on the entire surface.
A 0 nm Pd film, for example, a Pt film having a thickness of 100 nm and an Au film having a thickness of 300 nm, for example, are sequentially vacuum-deposited to form a p-side electrode 53 composed of a Pd / Pt / Au electrode,
Then, if necessary, heat treatment is performed to make the p-side electrode 53
Is ohmic-contacted with the p-type ZnTe contact layer 51. A portion of the p-side electrode 53 in contact with the p-type ZnTe contact layer 51 serves as a current passage. On the other hand, an n-side electrode 54 such as an In electrode is formed on the back surface of the n-type GaAs substrate 41.

Next, the n-type GaAs substrate 41 having the laser structure formed as described above is cleaved in a bar shape to form both resonator end faces, and then the front surface from which laser light is extracted, for example, by a vacuum deposition method. Al ₂ to the cavity end face side
A multi-layered film composed of an O ₃ film 55 and a Si film 56 is formed, and a multi-layered film in which the Al ₂ O ₃ film 55 and the Si film 56 are repeated for two cycles is formed on the end face of the resonator on the rear side from which laser light is not extracted. Form. Here, the Al ₂ O ₃ film 55 and the Si
The thickness of the multilayer film including the film 56 is selected so that the optical distance obtained by multiplying the refractive index by the film is ¼ of the oscillation wavelength of the laser light. By applying such an end face coating, for example, the reflectance of the front end face is 70%,
The reflectance of the rear end face can be set to 95%. After the end face coating is applied in this manner, the bar is cleaved to form chips, and packaging is performed.

In the semiconductor laser according to the third embodiment, the thickness of the i-type Zn _1-z Cd _z Se quantum well layer forming the active layer 45 is preferably 2 to 20 nm, for example 9n.
m.

In this case, n-type Zn _1-p Mg _p S _q
Se _1-q clad layer 43 and p-type Zn _1-p Mg _p S _q
The Mg composition ratio p of the Se _1-q clad layer 47 is, for example, 0.0
9, the S composition ratio q is, for example, 0.18, and the energy gap E _{g at} that time is about 2.94 eV at 77K. These n-type Zn _1-p Mg _p S _q Se _1-q having a Mg composition ratio p = 0.09 and an S composition ratio q = 0.18
Cladding layer 43 and p-type Zn _1-p Mg _p S _q Se _1-q
The clad layer 47 is lattice-matched with GaAs. Further, the Cd composition ratio z of the i-type Zn _1-z Cd _z Se quantum well layer forming the active layer 45 is, for example, 0.19, and the energy gap E _{g at} that time is about 2.54 eV at 77K.
At this time, the n-type Zn _1-p Mg _p S _q Se _1-q clad layer 43 and the p-type Zn _1-p Mg _p S _q Se _1-q clad layer 47 and the i-type Zn _1- constituting the active layer 45 are formed. _z Cd _z Se quantum well layer energy gap E _g difference ΔE
_g is 0.40 eV. The value of the energy gap E _g at room temperature is the energy gap E at 77K.
It can be determined by subtracting 0.1 eV from the value of _g .

In addition, n-type Zn_1-pMg_pS_qSe_1-qKu
The thickness of the rud layer 43 is, for example, 0.8 μm, n-type ZnS_u
Se_1-uThe thickness of the optical waveguide layer 44 is, for example, 60 nm, p-type Z
nS_uSe_1-uThe thickness of the optical waveguide layer 46 is, for example, 60 nm,
p-type Zn_1-pMg_pS_qSe _1-qThickness of clad layer 47
Is, for example, 0.6 μm, p-type ZnS_vSe_1-vLayer 48 thickness
For example, the p-type ZnSe contact layer 49 has a thickness of 0.6 μm.
Of the p-type ZnTe contact layer 5 has a thickness of, for example, 45 nm.
The thickness of 1 is 70 nm, for example.

Further, since the thickness of the n-type ZnSe buffer layer 42 has a slight lattice mismatch between ZnSe and GaAs, this n-type ZnSe buffer layer is caused by this lattice mismatch. In order to prevent dislocation from occurring during the epitaxial growth of the layer 42 and each layer thereon, it is selected to be sufficiently smaller than the critical film thickness of ZnSe (up to 100 nm), and here, for example, 33 nm is selected.

The p-type ZnS _v Se _1-v layer 48 on the p _- type Zn _1-p Mg _p S _q Se _1-q cladding layer 47 may be a p-type Zn _1-p Mg _p S layer depending on the case. functions as a second p-type cladding layer added to the _q Se _1-q cladding layer 47, a function of lattice matching with the p-type _{Zn 1-p Mg p S q} Se 1-q cladding layer 47, onto the heat sink It has one or two or more of the functions as a spacer layer for preventing a short circuit due to creeping up of solder on the chip end surface when mounting the laser chip. p-type Zn _1-p
Although there is a trade-off between the Mg composition ratio p and the S composition ratio q of the Mg _p S _q Se _1-q cladding layer 47, this p-type ZnS _v
The S composition ratio v of the Se _1-v layer 48 is selected within the range of 0 <v ≦ 0.1, preferably 0.06 ≦ v ≦ 0.08, and in particular, p-type Zn _1-p Mg _p S _The optimum S composition ratio v for achieving lattice matching with the _q Se _{1 -q} cladding layer 47 is 0.06.

The above-mentioned p-type ZnSe / ZnTe MQW layer 5
The reason for providing 0 is that when the p-type ZnSe contact layer 49 and the p-type ZnTe contact layer 51 are directly bonded, a large discontinuity occurs in the valence band at the bonding interface, which results from the p-side electrode 53 to the p-type ZnTe contact layer 51. This is to effectively eliminate this barrier because it becomes a barrier to holes injected into the.

That is, the carrier concentration in p-type ZnSe is typically about 5 × 10 ¹⁷ cm ⁻³ , while the carrier concentration in p-type ZnTe can be 10 ¹⁸ cm ⁻³ or more. is there. The discontinuity of the valence band at the p-type ZnSe / p-type ZnTe interface is about 0.8 eV. In the valence band of such a p-type ZnSe / p-type ZnTe junction, assuming that the junction is a step junction,
the p-type ZnSe side W = bending of (2εφ _T / qN _A) band across the width of the ^1/2 (1) occurs. Here, q is the absolute value of electron charge, ε is the dielectric constant of ZnSe, and φ _T is p.
Represents the discontinuous potential (about 0.8 eV) in the valence band at the ZnSe / p-type ZnTe interface.

At this time, the top of the valence band is p-type ZnS.
FIG. 13 shows how it changes along the direction perpendicular to the e / p-type ZnTe interface. However, here it is approximated that the Fermi levels of p-type ZnSe and p-type ZnTe coincide with the top of the valence band. As shown in FIG. 13, in this case, the valence band of p-type ZnSe is p-type Zn
It is bent downward (low energy side) toward Te.
This downward convex valence band change acts as a potential barrier for holes injected from the p-side electrode 53 into the p-type ZnSe / p-type ZnTe junction.

This problem is caused by the p-type ZnSe contact layer 4
9 and the p-type ZnTe contact layer 51 between the p-type ZnS
This can be solved by providing the e / ZnTe MQW layer 50. This p-type ZnSe / ZnTe MQW layer 5
0 is designed as follows by utilizing the fact that the ground quantum level E ₁ formed in the quantum well can be increased by reducing the width L _w of the quantum well.

In this case, the band bending generated over the width W from the p-type ZnSe / p-type ZnTe interface to the p-type ZnSe side is a quadratic function of the distance x from the p-type ZnSe / p-type ZnTe interface (FIG. 13). φ (x) = φ _T {1- (x / W) ² }
It is given in (2). Therefore, p-type ZnSe / ZnTe MQW
The layer 50 is designed based on the equation (2) such that the ground quantum level E ₁ formed in each of the quantum well layers made of p-type ZnTe has an energy at the top of the valence band of p-type ZnSe and p-type ZnTe. Can be performed by gradually changing L _W so as to be equal to each other and equal to each other.

FIG. 14 shows p-type ZnSe / ZnTeMQW.
A design example in which the width L _{B of the} barrier layer made of p-type ZnSe in the layer 50 is constant (for example, 2 nm) is shown. As shown in FIG. 14, in this case, the total width L _w of the seven quantum wells is set so that the ground quantum level E ₁ thereof coincides with the Fermi levels of p-type ZnSe and p-type ZnTe. It is gradually increased from the ZnSe contact layer 49 toward the p-type ZnTe contact layer 51.

In FIG. 14, the holes injected into the p-type ZnTe are resonantly tunneled through the ground quantum level E ₁ formed in each quantum well of the p-type ZnSe / ZnTe MQW layer 50 to the p-type ZnSe side. The potential barrier at the p-type ZnSe / p-type ZnTe interface effectively disappears. Therefore, according to the semiconductor laser of the third embodiment, good voltage-current characteristics can be obtained, and the operating voltage can be lowered.

When designing the width L _w of the quantum well, strictly speaking, since the levels of the respective quantum wells are coupled to each other, it is necessary to consider their interaction. Although the effect of strain due to the lattice mismatch between the well layer and the barrier layer must be taken into consideration, it is theoretically possible to set the quantum level of the multiple quantum well flat as shown in FIG.

As described above, according to the third embodiment,
Similar to the second embodiment, when epitaxially growing each p-type layer forming a laser structure, Di-PNH is used as a p-type dopant, and the growth is interrupted by interrupting the supply of the Group VI element material. Further, by performing annealing at a temperature of about 700 ° C. after the epitaxial growth, the carrier concentration of these p-type layers can be made sufficiently high. In addition, when the epitaxial growth of each n-type layer forming the laser structure is performed, the step of interrupting the growth by interrupting the supply of the raw material of the group II element is included to sufficiently increase the carrier concentration of these n-type layers. You can This makes it possible to realize a high-performance semiconductor laser that can emit light with a short wavelength and has a low threshold current density. More specifically, for example, it is possible to realize a green-emitting semiconductor laser capable of continuous oscillation at room temperature. It is also possible to reduce the applied voltage required for laser oscillation.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, in the third embodiment described above, S
The case where the present invention is applied to the manufacture of a semiconductor laser having a CH structure has been described, but the present invention can also be applied to the manufacture of a semiconductor laser having a DH structure (Double Heterostructure).

Furthermore, in the above-mentioned third embodiment, the case where the present invention is applied to the manufacture of a semiconductor laser has been described, but the present invention is applied to the manufacture of a light emitting diode using a II-VI compound semiconductor. It is also possible to apply it to the manufacture of various semiconductor devices using II-VI group compound semiconductors other than these semiconductor light emitting elements.

In the first to third embodiments described above, a GaAs substrate is used as the compound semiconductor substrate, but the compound semiconductor substrate is, for example, GaP.
A substrate or the like may be used.

The II-VI group compound semiconductor was MOC.
As a p-type dopant for epitaxial growth by the VD method or the MBE method using a gas source, for example, cyanamide (H—N = C = N—H), another atom is a double bond to the N atom. A bound organic compound may be used.

Further, an organic compound used as a p-type dopant in the present invention, that is, containing at least one nitrogen atom, and having a molecular weight of at least 12 at that nitrogen atom.
An organic compound in which at least two larger groups are bonded is a compound semiconductor containing nitrogen, such as GaN (II
It is possible to use it as an N source when growing a group IV compound semiconductor) by a vapor phase growth method.

[0106]

As described above, according to the present invention,
A nitrogen atom doped by a vapor phase growth method using a p-type dopant comprising an organic compound containing at least one nitrogen atom and at least two groups having a molecular weight of at least 12 are bonded to the nitrogen atom II -VI
A group compound semiconductor is grown, and after or during the growth,
At least a group II element or a group VI element having the highest vapor pressure among the group II element and the group VI element constituting the group II-VI compound semiconductor without covering the surface of the group II-VI compound semiconductor with the protective film is used. By performing the heat treatment of the II-VI group compound semiconductor at a temperature of 650 to 850 ° C. in the containing gas atmosphere, a p-type II-VI group compound semiconductor having a sufficiently high carrier concentration can be manufactured. Moreover, it is possible to prevent evaporation of the constituent elements and surface roughness.

[Brief description of drawings]

FIG. 1 is a MOCV used in a first embodiment of the present invention.
It is an approximate line figure showing the composition of D device.

FIG. 2 is a sequence diagram for explaining a method for manufacturing p-type ZnSe according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view for explaining the method for manufacturing p-type ZnSe according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing a temperature sequence of epitaxial growth and annealing in the method for manufacturing p-type ZnSe according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between the annealing temperature and the intensity ratio of DAP emission before and after annealing p-type ZnSe manufactured by the method for manufacturing p-type ZnSe according to the first embodiment of the present invention.

FIG. 6 is a graph showing an example of measurement results of photoluminescence spectra before and after annealing of a p-type ZnSe layer manufactured by the method for manufacturing p-type ZnSe according to the first embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the intensity ratio of DAP emission before and after annealing p-type ZnSe manufactured by the method for manufacturing p-type ZnSe according to the first embodiment of the present invention and the flow rate of DMSe flowing into the reaction tube of the MOCVD apparatus during annealing. It is a graph which shows.

FIG. 8 is a sequence diagram for explaining a method for manufacturing p-type ZnSe according to the second embodiment of the present invention.

FIG. 9 is a cross-sectional view for explaining the method for manufacturing p-type ZnSe according to the second embodiment of the present invention.

FIG. 10: NH produced by thermal decomposition of Di-PNH
FIG. 3 is a schematic diagram showing a state in which is bonded to Zn atoms on a Zn plane of a ZnSe crystal.

FIG. 11 is a cross-sectional view perpendicular to the cavity length direction of a semiconductor laser manufactured by the method for manufacturing a semiconductor laser according to the third embodiment of the present invention.

FIG. 12 is a sectional view parallel to the cavity length direction of a semiconductor laser manufactured by the method for manufacturing a semiconductor laser according to the third embodiment of the present invention.

FIG. 13 is an energy band diagram showing a valence band near a p-type ZnSe / p-type ZnTe interface.

FIG. 14 is a schematic diagram showing a design example of a p-type ZnSe / ZnTe MQW layer in a semiconductor laser according to a third embodiment of the present invention.

[Explanation of symbols]

21 Semi-insulating GaAs substrate 22 ZnSe: N layer 24 Adsorption layer of Zn and N 41 n-type GaAs substrate 42 n-type ZnSe buffer layer 43 n-type Zn _1-p Mg _p S _q Se _1-q clad layer 44 n-type ZnS _u Se _1-u optical waveguide layer 45 active layer 46 p-type ZnS _u Se _1-u optical waveguide layer 47 p-type Zn _1-p Mg _{p Sq} Se _1-q clad layer 48 p-type ZnS _v Se _1-v layer 49 p-type ZnSe contact layer 50 p-type ZnSe / ZnTe MQW layer 51 p-type ZnTe contact layer 52 insulating layer 53 p-side electrode 54 n-side electrode

Claims (13)

[Claims] 1. A raw material of a group II element, a raw material of a group VI element,
And, the nitrogen atom is doped by a vapor phase growth method using a p-type dopant comprising an organic compound containing at least one nitrogen atom and having at least two groups having a molecular weight of at least 12 greater than 12 bonded to the nitrogen atom. The grown II-VI compound semiconductor is grown, and the surface of the II-VI compound semiconductor is not covered with a protective film after the growth or during the growth, and
-Group II element and VI constituting a group VI compound semiconductor
Group II element or VI with the highest vapor pressure among group elements
650 in a gas atmosphere containing at least a group element
P-type II-VI, characterized in that the heat treatment of the II-VI group compound semiconductor is carried out at a temperature of ˜850 ° C.
Method for manufacturing group compound semiconductor. 2. The p-type I according to claim 1, wherein the heat treatment is performed at a temperature of 650 to 750 ° C.
A method for manufacturing a group I-VI compound semiconductor. 3. The p-type II-VI group compound semiconductor according to claim 1, wherein the heat treatment is performed in a reaction tube of a vapor phase growth apparatus used for growing the II-VI group compound semiconductor. Of manufacturing. 4. The method for producing a p-type II-VI group compound semiconductor according to claim 1, wherein the heat treatment is performed by resistance heating, high-frequency induction heating, or short-time heating by lamp light. 5. The method for producing a p-type II-VI group compound semiconductor according to claim 1, wherein the molecular weights of the two groups are larger than 36. 6. The method for producing a p-type II-VI group compound semiconductor according to claim 1, wherein the two groups have the same molecular weight. 7. The p-type dopant comprises an organic compound containing one nitrogen atom, and two hydrogen atoms having a molecular weight of more than 36 and one hydrogen atom are bonded to the nitrogen atom. The method for producing a p-type II-VI group compound semiconductor according to claim 1. 8. The p-type dopant comprises an organic compound containing one nitrogen atom, and three groups having a molecular weight of more than 36 are bonded to the nitrogen atom. A method for manufacturing a p-type II-VI compound semiconductor. 9. The organic compound is at least one organic compound selected from the group consisting of diisopropylamine, dipropylamine, dibutylamine, diisobutylamine, ditert-butylamine and ditertiarybutylamine. The p-type II- according to claim 7.
Method for manufacturing group VI compound semiconductor. 10. The organic compound is tripropylamine, triisopropylamine, tributylamine, triisobutylamine, tritert-butylamine, tritert-butylamine, diisopropylmethylamine, dipropylmethylamine, dibutylmethylamine, diisobutylmethyl. The method for producing a p-type II-VI group compound semiconductor according to claim 8, wherein the p-type II-VI compound semiconductor is at least one organic compound selected from the group consisting of amine, di-tert-butylmethylamine and ditertiarybutylmethylamine. 11. The II of the II-VI group compound semiconductor
The method for producing a p-type II-VI group compound semiconductor according to claim 1, wherein the nitrogen atom is delta-doped on the surface of the group element. 12. A step of interrupting the growth by maintaining the supply of the raw material of the group II element and the supply of the p-type dopant during the growth of the group II-VI compound semiconductor and interrupting the supply of the raw material of the group VI element. The method for producing a p-type II-VI group compound semiconductor according to claim 1, further comprising: 13. The production of a p-type II-VI group compound semiconductor according to claim 1, wherein the vapor phase growth method is a metal organic chemical vapor deposition method or a molecular beam epitaxy method using a gas source. Method.