JP2006319120A - Semiconductor laser and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser capable of injecting a uniform current into a gain unit by suppressing the Zn diffusion in the resonator lengthwise direction through the heat treatment upon the formation of a window structure. <P>SOLUTION: A first conductivity type clad layer 103, an active layer 104, second conductivity type clad layers 105 and 107, a second conductivity type intermediate layer 108, and a second conductivity type contact layer 109, are laminated in this order on a first conductivity type semiconductor substrate 101. The window structure is formed by adding a second conductivity type impurity to the light emitting end surface of the laminated structure consisting of the layers 103-109, and partition regions 205 containing a first conductivity type impurity are formed in the second conductivity type layers on both sides of the window region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor laser, and more particularly to a semiconductor laser having a window structure, which suppresses impurity (Zn) diffusion in the cavity length direction by heat treatment during the formation of the window structure, and reduces light absorption in an active layer in a gain region. The present invention relates to a structure of a semiconductor laser capable of a low threshold and a low operating current and a manufacturing method thereof.

  A semiconductor laser using an AlGaInP-based compound semiconductor is widely used as a light source for pick-up of an optical disk apparatus for processing a DVD or the like as a red laser having an oscillation wavelength of 650 nm.

  The demands of the DVD market are high-power red semiconductor lasers corresponding to higher speed and two-layer writing, and low operating current red semiconductor lasers corresponding to portable players. In particular, high-power red semiconductor lasers are required to operate stably at 300 mW or more, and the realization method thereof is to form melting and damage (COD: Catalytic Optical Damage) due to heat at the open end face by forming an end face window structure. In addition to suppression, the p-type cladding layer is doped with a high-concentration impurity to suppress overflow of current-injected carriers, and by increasing the thickness of the p-type cladding layer, the p-type contact It is essential to reduce the light absorption of the layer as much as possible. Further, in order to maintain a stable light output of 300 mW or more, there is no light absorption and uniform current injection in the gain region of the active layer that generates light.

A method of forming an end face window structure of a commonly used AlGaInP-based high-power red semiconductor laser will be described with reference to FIGS. As shown in the sectional view of the wafer in FIG. 1, an n-GaAs buffer layer 102 is formed on an n-GaAs substrate 101, and n- (Al _0.7 Ga _0.3 is formed on the n-GaAs buffer layer 102. ) _0.5 In _0.5 P cladding layer 103, active layer 104, first p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 105, p-Ga _0.5 In _0.5 P etching stop layer 106, second p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 107, p-Ga _0.5 In _0.5 P intermediate layer 108, a double heterojunction (DH) structure composed of a p-GaAs contact layer 109 is formed.

  In order to explain Zn diffusion in the window region in detail, FIG. 2A is an enlarged end view in the cross-sectional view of the wafer shown in FIG.

  FIG. 2-2 shows a case where ZnO 201 serving as a solid phase diffusion source of Zn is deposited on the p-GaAs contact layer 109 by a vapor deposition layer method (CVD) on the light emitting end face of the laminated structure. The resist 200 is applied to a portion that becomes a window region by a lithography process.

  Using the resist 200 as a mask, ZnO 201 is selectively etched with buffered hydrofluoric acid, and then the p-GaAs contact layer 109 that becomes the gain region 004 is selectively etched using a sulfuric acid-based etchant, as shown in FIG.

  FIG. 2-4 shows a dielectric film 202 formed on the entire surface of the wafer after etching the p-GaAs contact layer 109.

  After the formation of the dielectric film 202, solid phase diffusion of Zn in the ZnO 201 to the active layer 104 is performed by heat treatment (annealing) (FIG. 2-5). In the window region 003 where Zn is diffused by this treatment, the active layer 104 is disordered, and a window structure having a band gap larger than that of the active layer 104 is formed. In FIG. 2-5, reference numeral 203 denotes an actual Zn diffusion region when Zn is diffused into the window region 003. Reference numeral 204 denotes a region in which unintended Zn diffuses in the region 203 (gain regions 004 on both sides of the window region 003).

  Next, a method for forming an end face window structure in the same manner as described above in a state where the p-GaAs contact layer 109 serving as the gain region is left without being etched will be described in detail with reference to FIGS. explain.

  FIG. 3A shows a case where ZnO 201 serving as a solid phase diffusion source of Zn is formed on the p-GaAs contact layer 109 by a vapor deposition layer method (CVD) on the light emitting end face of the laminated structure. The resist 200 is applied to a portion that becomes a window region by a lithography process.

  FIG. 3-2 shows a case where the ZnO film 201 is selectively etched by buffered hydrofluoric acid using the resist 200 as a mask to form a dielectric film 202 on the entire surface of the wafer.

  After the formation of the dielectric film 202, Zn in the ZnO 201 is solid-phase diffused by annealing and diffused to the active layer (FIG. 3-3). In the window region 003 where Zn is diffused by this treatment, the active layer 104 is disordered, and a window structure having a band gap larger than that of the active layer 104 is formed. In FIG. 3C, reference numeral 203 denotes an actual Zn diffusion region when Zn is diffused into the window region 003. Reference numeral 204 denotes a region in which unintended Zn diffuses in the region 203 (gain regions 004 on both sides of the window region 003).

  The Zn diffusion method using the above solid phase diffusion source diffuses in the stacking direction (depth direction) from the p-GaAs contact layer 109 to the active layer 104 by annealing. This method is sufficiently disordered in the window region 003, but Zn is diffused in the active layer 104 in the gain region 004 on both sides of the window region 003 (region 204). Happens. In the region 204 in which Zn is diffused, the band gap energy becomes larger than the oscillation wavelength because slight disorder occurs. Theoretically, no light is absorbed in that region, but since the difference between the oscillation wavelength and the band gap energy is small, light absorption actually occurs and a loss occurs. As a result, there is a problem that a high threshold value and a high operating current are used and the reliability of the semiconductor laser is impaired.

As a cause of the diffusion (204) of Zn into the gain region 004 at the time of annealing, it is diffused into the gain region 004 at the initial stage of Zn diffusion due to the influence of strain generated at the interface between the dielectric film 202 and the semiconductor layer. As a result, it is estimated that lateral diffusion is promoted particularly in the (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P layer) because the P-based material is more easily diffused. The Zn diffusion profiles shown in FIGS. 2-5 and 3-3 are obtained.

As an example of manufacturing a highly reliable semiconductor laser by grasping the problems of the conventional window structure forming method from another viewpoint and devising it, there are structures and manufacturing methods as shown in Patent Documents 1 and 2, for example. Proposed.
JP 11-26866 A Japanese Patent Laid-Open No. 2003-142774

  However, the above prior art suppresses the reactive current flowing in the window region 003 by implanting protons from the outermost surface layer of the window region 003, or converts the n-type cladding layer in the window region 003 to p-type. This is a method of improving the characteristics and reliability of the device by making the window region 003 non-injected by making the cladding layer n-type. However, it is not possible to suppress the diffusion (204) of Zn to the active layer 104 in the gain region 004 on both sides of the window region 003 during annealing at the time of forming the window structure. As a result, the problem that Zn is diffused (204) in the active layer 104 on both sides of the window region 003 and unintended disordering occurs cannot be solved. Similarly, since Zn is diffused in the cladding layer, the region has an adverse effect on reliability because Zn is easily diffused into the active layer during energization or in a thermal process. For this reason, when the window structure is formed, it is possible to suppress the diffusion (204) of impurities into the active layer 104 in the gain region 004 on both sides of the window region 003. It is essential to make possible semiconductor lasers.

  Therefore, the object of the present invention is to suppress the diffusion of impurities to the active layer in the gain region on both sides of the window region due to annealing during the formation of the window structure. An object of the present invention is to provide a semiconductor laser capable of obtaining an output and highly reliable laser characteristics.

  In order to solve the above-described problems, a semiconductor laser according to the present invention includes a first conductivity type cladding layer, an active layer, a second conductivity type cladding layer, and a second conductivity type contact layer on a first conductivity type semiconductor substrate. It has a laminated structure laminated in order, has a window region formed by adding a second conductivity type impurity on the light emitting end face of the laminated structure, and contains a first conductivity type impurity in the second conductivity type layer on both sides of the window region A partition area.

  According to this configuration, the partition having the window region formed by adding the second conductivity type impurity on the light emitting end face of the laminated structure, and the second conductivity type layer on both sides of the window region containing the first conductivity type impurity. Since the region is provided, diffusion of the second conductivity type impurity to the gain region can be suppressed during energization.

  Without the partition region, the high-concentration second conductivity type impurity diffuses into the second conductivity type cladding layer and the active layer near the window region. As a result, not only unintentional disorder occurs, but Zn diffused during energization diffuses into the active layer, and a semiconductor laser having a low threshold, high reliability, and high output cannot be manufactured.

  By injecting the first conductivity type impurity, when the second conductivity type impurity is diffused, it is ion-bonded with the first conductivity type impurity, so that diffusion to the second conductivity type cladding layer and the active layer can be suppressed, Since there is no light absorption and uniform current injection is possible, a semiconductor laser capable of high output with a low threshold is obtained.

In the semiconductor laser of the present invention, it is preferable that the partition region is formed in the second conductivity type contact layer. Moreover, the partition area | region may be formed in the said 2nd conductivity type clad layer. A partition region may be formed in the second conductivity type cladding layer and the second conductivity type contact layer. The first conductivity type impurity contained in the partition region is added by, for example, ion implantation. The impurity concentration of the first conductivity type implanted in the partition area is preferably ^{1 × 10 16 cm -3 ~1 ×} 10 20 cm -3. Moreover, it is preferable that the width | variety of a partition area | region is 1 micrometer-10 micrometers. Moreover, it is preferable that the 1st conductivity type impurity contained in a partition area | region is either Si, Se, or Te.

  The method of manufacturing a semiconductor laser according to the present invention includes a first step of forming a first conductivity type cladding layer on a first conductivity type semiconductor substrate while adding a first conductivity type impurity; And a second step of forming a second conductivity type cladding layer, a second conductivity type cap layer, and a second conductivity type contact layer on the active layer while adding a second conductivity type impurity. 3 steps, and a fourth step of forming a window region by adding an impurity to the light emitting end face of the laminated structure formed by the first step, the second step, and the third step. In the fourth step, a window region is formed. After the first conductivity type impurity is added to the second conductivity type layers on both sides of the region to form the partition region, the second conductivity type impurity is added to the region between the partition regions by solid phase diffusion, and the window region Form.

  According to this method, after the first conductivity type impurity is added to the second conductivity type layer on both sides of the region to be the window region to form the partition region, the second conductivity type impurity is added to the region between the partition regions. Since the window region is formed by addition by solid phase diffusion, light absorption does not occur by suppressing impurity diffusion to the active layer in the gain region on both sides of the window region due to annealing at the time of forming the window structure. A semiconductor laser capable of obtaining a high output and highly reliable laser characteristic with a threshold value and a low operating current can be obtained.

In the semiconductor laser manufacturing method of the present invention, the active layer is preferably formed in a multilayer structure. In the fourth step, it is preferable to perform ion implantation so that the concentration of the first conductivity type impurity contained in the partition region is 1 × 10 ¹⁶ cm ⁻³ to 1 × 10 ²⁰ cm ⁻³ .

  According to the present invention, by providing the partition region, it is possible to suppress the impurity diffusion to the active layer in the gain region on both sides of the window region in the annealing at the time of forming the window structure. Therefore, it is possible to provide a semiconductor laser having a low threshold without light absorption, a high operating current and a high output.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a semiconductor laser having a laminated structure according to the present invention. The semiconductor laser in the present embodiment has the following structure.

An n-GaAs buffer layer 102 (Si doped, 7.0 × 10 ¹⁷ ) on an n-GaAs substrate 101 (Si doped, dopant concentration: 7.0 × 10 ¹⁷ cm ⁻³ , hereinafter, only the value is described for the dopant concentration). cm ⁻³ ) with a thickness of 0.5 μm. The buffer layer 102 is necessary for improving the crystallinity of the cladding layers 103, 105, 107, the active layer 104, and the like described below.

On the n-GaAs buffer layer 102, an n- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 103 (Si-doped, 7.0 × 10 ¹⁷ cm ^{− having a} thickness of 2.0 μm is formed. ³ ), 92 nm thick active layer 104 (non-doped), 240 nm thick first p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 105 (Zn doped amount, 9.0) × 10 ¹⁷ cm ⁻³ ), 10 nm thick p-Ga _0.5 In _0.5 P etching stop layer 106 (Zn-doped, 1.5 × 10 ¹⁸ cm ⁻³ ), 1.35 μm thick second p -(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 107 (Zn-doped, 1.2 × 10 ¹⁸ cm ⁻³ ), 50 nm thick p-Ga _0.5 In _0.5 P intermediate layer 108 (Zn-doped, 1.5 × ¹⁰ 18 cm ^3), 200 nm thick p-GaAs contact layer 109 (Zn-doped heterojunction structure section is formed into a double consisting 1.5 × ¹⁰ 18 ^{cm -3).}

  The composition of each of the above layers is an example, and the lattice constants of the double heterojunction layers 103 to 107 and the intermediate layer 108 are substantially equal to those of the n-GaAs substrate 101, and the cladding layers 103, 105, and 107, and the etching stop layer 106 are included. The composition of In, Ga, and Al is determined so that the band gap energy of the intermediate layer 108 is larger than the band gap energy of the active layer 104. Note that all the layers are formed by crystal growth by the metal organic chemical vapor deposition layer method (MOCVD method), and impurities in each layer are added simultaneously when the respective layers are crystal-grown.

  The Zn diffusion in the window structure formation will be described in detail. In order to selectively etch the p-GaAs contact layer 109 on both sides of the window region 003 on the light emitting end face of the laminated structure, a resist 200 is applied using a photolithography process, and the p-GaAs contact layer 109 is made of a sulfuric acid-based etchant. Those removed using are shown in FIG. 4-1.

In order to suppress Zn diffusion into the active layer 204 (see FIGS. 2-5 and 3-3) in the gain region 004 on both sides of the window region 003 due to annealing, ion implantation is performed using Si as an implantation source using the resist 200 as a mask. The result is shown in FIG. In FIG. 4B, reference numeral 205 denotes a partition region formed by ion implantation of Si that is an n-type impurity. The width of the partition region 205 is preferably in the range of 1 μm to 10 μm. The first conductivity type impurity concentration contained in the partition region 205 is preferably 1 × 10 ¹⁶ cm ⁻³ to 1 × 10 ²⁰ cm ⁻³ .

  After the implantation, the resist 200 is removed with an organic solvent, and ZnO 201 is formed on the entire wafer surface as shown in FIG.

  FIG. 4-4 shows a case where a resist 206 is applied to the window region 003 using a photolithography process in order to remove ZnO other than the window region 003.

  4-5 shows a case where ZnO 201 is selectively etched with buffered hydrofluoric acid using the resist 206 as a mask, and then the p-GaAs contact layer 109 in the gain region 004 is selectively etched using a sulfuric acid-based etchant.

After the p-GaAs contact layer 109 is etched, SiO ₂ 202 is formed on the entire surface of the wafer, and Zn in the ZnO 201 is solid-phase diffused by annealing and diffused to the active layer 104 (FIG. 4-6). In the window region 003 where Zn is diffused by this treatment, disordering of the active layer 104 occurs, and a window structure 003 having a band gap larger than that of the active layer 104 is formed. Reference numeral 203 denotes a Zn diffusion region (a region where sufficient disorder has been achieved).

  The conventional window structure forming method causes a problem that Zn is diffused into the active layer in the gain region 004 as described in the problem. In the first embodiment of the present invention, the first conductivity type (n-type) impurity is used. In the partition region 205 formed by injecting Si, Zn and Si are attracted to each other by ionic bonding, so that further diffusion into the gain region 004 can be suppressed. Therefore, Zn can be diffused only in the stacking direction (depth direction) of the window region 003 as shown in FIG. 4-6. Further, even if the ion implantation depth is limited to the p-GaInP intermediate layer 108, lateral Zn diffusion can be suppressed as compared with the conventional window structure formation. The partition region 205 can also be formed by injecting Se or Te.

FIG. 6 and FIG. 7 show the device structure formed after the window structure is formed. 7 is a cross-sectional view taken along the line α-β in FIG. On the side of the ridge composed of the second p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 107, an n-Al _0.5 In _0.5 P current having a thickness of 300 nm is provided. Block layer 110 (Si-doped, 5.0 × 10 ¹⁷ cm ⁻³ ) is formed, and p-Ga _0.5 In _0.5 P intermediate layer 108 and n-Al _0.5 In _0.5 P current blocking layer are formed. A p-GaAs contact layer 111 (Zn-doped, 5 × 18 ¹⁸ cm ⁻³ ) having a thickness of 3.0 μm is formed on 110. A p-side electrode 113 is formed on the upper surface of the p-GaAs contact layer 111, and an n-side electrode 112 is formed on the lower surface of the n-GaAs substrate 101.

  By performing such a layer structure and process, Zn diffusion to the active layer 204 (see FIGS. 2-5 and 3-3) in the gain region 004 on the side surface of the window region 003 can be suppressed, and unintended disordering can be achieved. Since it is not formed, a high output semiconductor laser capable of high reliability with a low threshold and a low operating current can be realized. Further, it is possible to suppress the diffusion of the second conductivity type impurity to the gain region during energization.

  Without the partition region, the high-concentration second conductivity type impurity diffuses into the second conductivity type cladding layer and the active layer near the window region. As a result, not only unintentional disorder occurs, but Zn diffused during energization diffuses into the active layer, and a semiconductor laser having a low threshold, high reliability, and high output cannot be manufactured.

  By injecting the first conductivity type impurity, when the second conductivity type impurity is diffused, it is ion-bonded with the first conductivity type impurity, so that diffusion to the second conductivity type cladding layer and the active layer can be suppressed, Since there is no light absorption and uniform current injection is possible, a semiconductor laser capable of high output with a low threshold is obtained.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. Since the laminated structure of the second embodiment is the same as that of the first embodiment, it will be described with reference to FIG.

An n-GaAs buffer layer 102 (Si doped, 7 μm thick) on an n-GaAs substrate 101 (Si doped, dopant concentration: 7.0 × 10 ¹⁷ cm ⁻³ ; 0.0 × 10 ¹⁷ cm ⁻³ ). The buffer layer 102 is necessary for improving the crystallinity of the cladding layers 103, 105, 107, the active layer 104, and the like described below.

On the n-GaAs buffer layer 102, an n- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 103 (Si-doped, 7.0 × 10 ¹⁷ cm ^{− having a} thickness of 2.0 μm is formed. ³ ), 92 nm thick active layer 104 (non-doped), 240 nm thick first p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 105 (Zn doped amount, 9.0) × 10 ¹⁷ cm ⁻³ ), 10 nm thick p-Ga _0.5 In _0.5 P etching stop layer 106 (Zn-doped, 1.5 × 10 ¹⁸ cm ⁻³ ), 1.35 μm thick second p -(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 107 (Zn-doped, 1.2 × 10 ¹⁸ cm ⁻³ ), 50 nm thick p-Ga _0.5 In _0.5 P intermediate layer 108 (Zn-doped, 1.5 × ¹⁰ 18 cm ^3), heterojunction structure section is formed into a double consisting 200nm thick p-GaAs contact layer 109 (Zn-doped).

Regarding the carrier concentration of the p-GaAs contact layer 109, the first 100 nm (lower layer side) is doped by 1.5 × 10 ¹⁸ cm ⁻³ , and the remaining 100 nm (upper layer side) is 3.0 × 10 ¹⁹ cm ^−3. Doped.

Here, the reason why the carrier concentration of the p-GaAs contact layer 109 is different between the upper layer and the lower layer will be described. Since the contact area between the p-type electrode and the p-GaAs contact layer is very small, if the contact layer concentration is not 3.0 × 10 ¹⁹ cm ⁻³ , the contact resistance between the electrode and the semiconductor is increased and the characteristics are not good (operation) Voltage rise, chip temperature rise). However, if this concentration is in the lower layer, Zn diffuses into the cladding layer and the active layer and adversely affects the reliability, so the concentration in the lower layer is reduced by one digit.

  The composition of each of the above layers is an example, and the lattice constants of the double heterojunction layers 103 to 107 and the intermediate layer 108 are substantially equal to those of the n-GaAs substrate 101, and the cladding layers 103, 105, and 107, and the etching stop layer 106 are included. The composition of In, Ga, and Al is determined so that the band gap energy of the intermediate layer 108 is larger than the band gap energy of the active layer 104. Note that all the layers are formed by crystal growth by the metal organic chemical vapor deposition layer method (MOCVD method), and impurities in each layer are added simultaneously when the respective layers are crystal-grown.

  The Zn diffusion in the window structure formation will be described in detail. In order to suppress Zn diffusion to the active layer 104 in the gain region 004 due to annealing on the light emitting end face of the laminated structure, a resist 200 is applied as shown in FIG.

  FIG. 5B shows a case where the resist 200 is used as a mask and ions are implanted using Si as an implantation source. In FIG. 5B, reference numeral 205 denotes a partition region formed by ion implantation of Si that is an n-type impurity.

  After the implantation, the resist 200 is removed with an organic solvent, and ZnO 201 is formed on the entire surface of the wafer. In order to remove ZnO 201 other than the window region 003, a resist 206 applied to the window region using a photolithography process is shown in FIG.

FIG. 5-4 shows a case where ZnO 201 is selectively etched by buffered hydrofluoric acid using the resist 206 as a mask to form SiO ₂ 202 on the entire surface of the wafer.

  By annealing, Zn in ZnO 201 is solid-phase diffused and diffused to the active layer 104 (FIGS. 5-5). In the window region 003 where Zn is diffused by this treatment, the active layer 104 is disordered, and a window structure having a band gap larger than that of the active layer 104 is formed. In FIG. 5-5, reference numeral 203 denotes a region where Zn is diffused only in the window region 003, and indicates a region where sufficient disorder has been achieved.

  In the conventional window structure forming method, as described in the problem, there arises a problem that Zn is diffused into the active layer in the gain region. In the second embodiment of the present invention, the first conductivity is the same as in the first embodiment. In the partition region 205 formed by implanting Si, which is a mold, Zn and Si attract each other by ionic bonding or the like, so that further diffusion into the gain region can be suppressed.

  From this, Zn can be diffused in the stacking direction (depth direction) of the window region as shown in FIG. Further, even if the ion implantation is performed only in the p-GaAs contact layer 109 or only in the p-GaAs contact layer 109 and the p-GaInP intermediate layer 108, the lateral Zn diffusion is more than that in the conventional window structure formation. It is possible to hold down.

FIG. 8 and FIG. 9 show the device structure formed after the window structure is formed. 9 is a cross-sectional view taken along the line α-β in FIG. A SiN current blocking film 110 having a thickness of 300 nm is formed on the ridge side portion and the window region formed of the second p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 107. A p-side electrode 113 is formed on the p-GaAs contact layer 109, and an n-side electrode 112 is formed on the lower surface of the n-GaAs substrate 101. In addition, ridge portions insulated by SiN110 are provided at both ends of the ridge so that the p-electrode can be stably bonded to the submount.

  By performing such a layer structure and process, Zn diffusion to the active layer in the gain region on both sides of the window region can be suppressed, and unintentional disordering is not formed. It is possible to realize a high-power semiconductor laser that can be operated.

  The semiconductor laser according to the present invention can realize a semiconductor laser having a low threshold, a low operating current, a high output and a high reliability, and is particularly useful when applied to a red semiconductor laser used for a DVD or the like.

It is sectional drawing which shows the laminated structure of the semiconductor laser in embodiment of this invention. It is an enlarged view of the XY part in FIG. It is sectional drawing in order of a process which shows the formation method of the window structure of the conventional semiconductor laser. It is sectional drawing in order of a process which shows the formation method of the window structure of the conventional semiconductor laser. It is sectional drawing in order of a process which shows the formation method of the window structure of the conventional semiconductor laser. It is sectional drawing in order of a process which shows the formation method of the window structure of the conventional semiconductor laser. It is process order sectional drawing which shows the formation method of the window structure of the other conventional semiconductor laser. It is process order sectional drawing which shows the formation method of the window structure of the other conventional semiconductor laser. It is process order sectional drawing which shows the formation method of the window structure of the other conventional semiconductor laser. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 1 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 2 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 2 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 2 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 2 of this invention. It is process order sectional drawing which shows the formation method of the window structure of the semiconductor laser of Embodiment 2 of this invention. It is sectional drawing which looked at the semiconductor laser of Embodiment 1 of this invention from the light emission direction. It is sectional drawing which looked at the semiconductor laser of Embodiment 1 of this invention from the cavity end surface direction. It is a bird's-eye view of the semiconductor laser of Embodiment 2 of this invention. It is sectional drawing which looked at the semiconductor laser of Embodiment 2 of this invention from the cavity end surface direction.

Explanation of symbols

101 n-GaAs substrate 102 n-GaAs buffer layer 103 n-AlGaInP cladding layer 104 active layer (strained quantum well active layer)
105 first p-AlGaInP cladding layer 106 p-GaInP etching stop layer 107 second p-AlGaInP cladding layer 108 p-GaInP intermediate layer 109 p-GaAs contact layer 110 dielectric film (SiN)
200 Resist film 201 ZnO film 202 Dielectric film (SiO ₂ )
203 Zn diffusion region (region where sufficient disorder has been achieved)
204 Active layer in gain region on side of window region 205 Partition region

Claims (11)

A semiconductor laser comprising a laminated structure in which a first conductivity type cladding layer, an active layer, a second conductivity type cladding layer, and a second conductivity type contact layer are laminated in this order on a first conductivity type semiconductor substrate,
The light emitting end face of the laminated structure has a window region formed by adding a second conductivity type impurity, and the second conductivity type layer on both sides of the window region has a partition region containing a first conductivity type impurity. A semiconductor laser characterized by the above.   The semiconductor laser according to claim 1, wherein the partition region is formed in the second conductivity type contact layer.   2. The semiconductor laser according to claim 1, wherein the partition region is formed in the second conductivity type cladding layer.   2. The semiconductor laser according to claim 1, wherein the partition region is formed in the second conductivity type cladding layer and the second conductivity type contact layer.   The semiconductor laser according to claim 1, wherein the first conductivity type impurity contained in the partition region is added by ion implantation. 6. The semiconductor laser according to claim 5, wherein an impurity concentration of the first conductivity type ion-implanted into the partition region is 1 × 10 ¹⁶ cm ⁻³ to 1 × 10 ²⁰ cm ⁻³ .   The semiconductor laser according to claim 1, wherein the partition region has a width of 1 μm to 10 μm.   The semiconductor laser according to claim 1, wherein the first conductivity type impurity contained in the partition region is any one of Si, Se, and Te. A first step of forming a first conductivity type cladding layer on the first conductivity type semiconductor substrate while adding a first conductivity type impurity;
A second step of forming an active layer on the first conductivity type cladding layer;
Forming a second conductivity type cladding layer, a second conductivity type cap layer, and a second conductivity type contact layer on the active layer while adding a second conductivity type impurity;
A method of manufacturing a semiconductor laser, comprising: a fourth step of forming a window region by adding an impurity to the light emitting end face of the laminated structure formed by the first step, the second step, and the third step,
In the fourth step, the partition region is formed by adding the first conductivity type impurity to the second conductivity type layer on both sides of the region to be the window region, and then the second conductivity type impurity is formed in the region between the partition regions. A method of manufacturing a semiconductor laser, wherein the window region is formed by adding solid phase diffusion.   10. The method of manufacturing a semiconductor laser according to claim 9, wherein, in the second step, the active layer is formed in a multilayer structure. The ion implantation is performed in the fourth step so that the concentration of the first conductivity type impurity contained in the partition region is 1 × 10 ¹⁶ cm ⁻³ to 1 × 10 ²⁰ cm ^−3. A method for producing a semiconductor laser as described in 1. above.

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