Semiconductor laser with carrier limiting effect and preparation method thereof

Abstract

The invention relates to a semiconductor laser with a carrier limiting effect and a preparation method thereof, and belongs to the technical field of semiconductor lasers, a carrier limiting region structure is added on the light-emitting surface side of a high-power semiconductor laser, and a carrier limiting region contact layer is made of a low-doped epitaxial material, so that the carrier limiting region contact layer is in Schottky contact with a semiconductor; a high potential barrier is formed at a metal contact interface, the injection current distribution of a light-emitting surface is controlled, and the band gap shrinkage phenomenon caused by heat accumulation under working current is effectively reduced, so that the cavity surface reliability of the semiconductor laser is improved. The carrier confinement region can control the heat dissipation path to reduce the difference of thermally induced refractive indexes, thereby preventing the effective refractive index of the active region from rising due to temperature rise, and suppressing the thermal lens effect. On the other hand, the accumulation effect and lateral expansion of current carriers can be limited, so that the phenomenon that more high-order modes are excited under working current is reduced, and the lateral light beam quality is improved.

Description

Technical Field

[0001] The invention relates to a semiconductor laser with carrier limiting function and a preparation method thereof, belonging to the technical field of semiconductor lasers. Background Art

[0002] High-power semiconductor lasers have the advantages of small mass, small size, easy integration, and high efficiency. They are widely used in laser communications, material processing, laser medical treatment and other fields. With the continuous development of application fields, the requirements for the optoelectronic performance parameters of lasers are gradually increasing. Not only high output power is pursued, but also high beam quality and high cavity surface damage threshold need to be guaranteed at high power. In traditional ridge lasers, narrow strip width is usually controlled to improve beam quality, but at the same time, the output power is often low due to the narrow strip width. The output power of wide-strip lasers will be greatly improved, but according to waveguide mode theory, wide-strip lasers will produce more lateral high-order modes when injecting working current, resulting in poor lateral beam quality. In addition, wide-strip lasers will also be accompanied by lateral carrier leakage, thermal lens effect and carrier accumulation effect during operation, and the occurrence of these phenomena will aggravate the deterioration of lateral beam quality.

[0003] After the metal and semiconductor in the semiconductor laser come into contact, due to the difference in their work functions, the semiconductor energy band near the interface will bend. Different differences will lead to different energy band bends, and eventually different types of contacts are formed, which can be divided into Ohmic contact and Schottky contact. If the metal work function is greater than the semiconductor work function, the interface material energy band will bend upward after contact, and a negligible thin space charge region will be formed on the metal side, while a thick space charge region will be formed on the semiconductor side. Electrons need to cross a potential barrier to move, and this contact is called Schottky contact. If the metal work function is less than the semiconductor work function, the interface material energy band will bend downward after contact, forming a cumulative Ohmic contact. Summary of the invention

[0004] In view of the problem that the high power and high beam quality of the above-mentioned high-power semiconductor lasers cannot be improved at the same time, the present invention provides a semiconductor laser with carrier confinement function and a preparation method thereof.

[0005] The core technology of the present invention is to add a carrier confinement region structure on the light-emitting side of a high-power semiconductor laser. The epitaxial layer of the carrier confinement region is a low-doped epitaxial material, so that it forms a Schottky contact with the semiconductor, and a higher potential barrier is formed at the metal contact interface, thereby controlling the distribution of the injected current on the light-emitting surface, effectively reducing the band gap shrinkage phenomenon caused by heat accumulation under the working current, thereby improving the cavity surface reliability of the semiconductor laser. On the other hand, controlling the heat dissipation path reduces the thermally induced refractive index difference, avoiding the increase in the effective refractive index due to the temperature rise in the active area, thereby suppressing the thermal lens effect. The carrier confinement region can also limit the accumulation effect and lateral expansion of carriers, thereby reducing the phenomenon of exciting more high-order modes under the working current and improving the lateral beam quality.

[0006] The present invention firstly grows epitaxial layers with different doping concentrations, then prepares ridge stripes and grooves by wet etching, grows insulating layers, prepares P-surface electrodes and carrier control regions by electron beam evaporation, performs backside thinning and metal growth on the epitaxial wafer, and performs high-temperature annealing on the semiconductor laser.

[0007] The technical solution of the present invention is as follows:

[0008] A semiconductor laser with carrier confinement function, divided into a front cavity surface part and a back cavity surface part, the front cavity surface part comprises, from bottom to top, an N-face metal layer, a substrate, a buffer layer, an N-face confinement layer, an N-face waveguide layer, a well layer, a P-face waveguide layer, and a P-face confinement layer, low-doped contact layers are arranged at both ends above the P-face confinement layer, a high-doped contact layer is arranged above the P-face confinement layer between the low-doped contact layers at both ends, the thickness of the high-doped contact layer is greater than that of the low-doped contact layer, a carrier confinement region metal layer is arranged above the low-doped contact layers at both ends, and a P-face electrode metal layer is arranged on the side between the high-doped contact layer and the carrier confinement region metal layer and above the high-doped contact layer; The back cavity surface part is respectively composed of N-face metal layer, substrate, buffer layer, N-face confinement layer, N-face waveguide layer, well layer, P-face waveguide layer and P-face confinement layer from bottom to top. A high-doped contact layer is arranged above the P-face confinement layer. The high-doped contact layer is a convex layer with high middle and low sides. The high middle part of the high-doped contact layer of the back cavity surface forms a ridge with the high-doped contact layer of the front cavity surface. In the back cavity surface part, grooves are etched downward on both sides of the ridge, and the bottom of the groove is in the P-face waveguide layer. An insulating layer is arranged above the high-doped contact layer on both sides of the ridge, on the side walls of the ridge, and at both ends of the top surface of the ridge. A P-face electrode metal layer is arranged above the insulating layer and the high-doped contact layer not covered by the insulating layer.

[0009] Preferably, in the rear cavity surface portion, the cross-sectional shape of the groove is a trapezoid, with the short side at the bottom.

[0010] Preferably, in the front cavity surface part, the doping concentration of the low-doped contact layer is 1×10 14 -1×1017 Pieces / cm -3 The doping concentration of the high-doped contact layer in the front cavity surface and the back cavity surface is 1×10 18 -1×10 20 Pieces / cm -3 .

[0011] Preferably, the highly doped contact layers in the front cavity surface portion and the back cavity surface portion have the same width, and their top surfaces are located at the same horizontal plane to form a ridge with a ridge width of 100 μm-200 μm and a ridge length of 1000 μm-5000 μm.

[0012] Preferably, the trench etching depth is 100 nm-200 nm, the trench short side width is 5 μm-10 μm, and the distance between the two side edges of the trench short side and the ridge is 20 μm-50 μm.

[0013] Preferably, the P-side electrode metal layer is Ti / Pt / Au or Ti / Cr / Au or Ti / Ag / Au.

[0014] Furthermore, the thickness of the P-side electrode metal layer is 10nm-100nm / 10nm-100nm / 100nm-500nm.

[0015] Preferably, the N-side metal layer is Ni / Ge / Au or Ni / Ti / Au or Ni / V / Au.

[0016] Furthermore, the thickness of the N-side metal layer is 10nm-100nm / 10nm-100nm / 50nm-300nm.

[0017] Preferably, the insulating layer is SiO2, the metal layer in the carrier confinement region is a metal-semiconductor structure, the metal is selected from Ni, Au, Al, Pt, and the semiconductor is a doping concentration less than or equal to 1×10 17 Pieces / cm -3 Low-doped GaAs, the carrier confinement region length is 100μm-400μm.

[0018] A method for preparing a semiconductor laser having a carrier confinement effect comprises the following steps: (1) Growth of epitaxial layers with different doping concentrations, where the epitaxial layers include a contact layer, a confinement layer, a waveguide layer, and a well layer, wherein the contact layer is made of materials with different doping concentrations; According to the preferred embodiment of the present invention, the contact layer is made of GaAs semiconductor material; it is divided into a low-doped contact layer and a high-doped contact layer according to different doping concentrations; the doping is Mg doping, wherein the doping concentration of the low-doped contact layer is 1×10 14 -1×10 17 Pieces / cm -3The doping concentration of the highly doped contact layer is 1×10 18 -1×10 20 Pieces / cm -3 .

[0019] (2) Ridge stripe preparation: the ridge stripe is prepared by wet etching, wherein the wet etching is chemical etching in an acidic solution, and the wet etching obtains the ridge stripe width of 100 μm-200 μm, the ridge stripe length of 1000 μm-5000 μm, and the etching depth of 100 nm-200 nm; (3) Groove preparation. The grooves are arranged on both sides of the ridge to limit the beam path, reduce the scattering of the beam during propagation, improve the beam quality, and isolate the current. The width of the short side of the groove is 5 μm-10 μm, and the etching depth reaches the P-face waveguide layer; the distance between the two sides of the short side of the groove and the ridge is 20 μm-50 μm; (4) Insulating layer growth: Insulating layer growth is performed by PECVD to prevent current leakage under the working current of the laser; the insulating layer is SiO2; (5) Preparation of the P-side electrode metal layer. The P-side electrode metal layer is prepared by electron beam evaporation and the pattern is prepared by a lift-off process. The P-side electrode metal layer area is a high-doped area of ​​the contact layer and is lift-off by negative photoresist. (6) Preparation of the metal layer in the carrier confinement area. The contact layer in the carrier confinement area is a low-doped contact layer. In order to further confine the carriers, increase the barrier height, and reduce the tunneling effect, a Schottky contact structure is prepared.

[0020] Preferably, in step (6), the Schottky contact structure (i.e., the carrier confinement region) has a length of 100 μm to 400 μm, and the length direction is the length direction between the front cavity surface and the rear cavity surface (i.e. Figure 3 The vertical length of the middle), its structure is a metal-semiconductor structure, and the metal is prepared by electron beam evaporation; (7) Preparation of back electrode: thinning and metal evaporation of the back side of the epitaxial wafer. The back side is thinned so that the thickness of the metal layer from the N-side metal layer to the P-side electrode of the entire wafer is 120 μm-150 μm. Electron beam evaporation is used to prepare the back side metal layer electrode; (8) The semiconductor laser is subjected to rapid high temperature annealing at a temperature of 400°C-500°C, an annealing time of 1-3 minutes, and an annealing atmosphere of nitrogen.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention adds a carrier confinement region structure on the light-emitting surface side of a high-power semiconductor laser, and adopts Schottky contact at the metal contact interface in the confinement region to form a higher potential barrier, control the injection current distribution of the light-emitting surface, and effectively reduce the band gap shrinkage phenomenon caused by heat accumulation under the working current, thereby improving the cavity surface reliability of the semiconductor laser.

[0023] 2. The present invention controls the heat dissipation path by setting different doping concentrations, reduces the difference in thermally induced refractive index, avoids the increase in effective refractive index due to temperature rise in the active area, and thus suppresses the thermal lens effect.

[0024] 3. Since the gold-semiconductor contact barrier in the carrier confinement area is relatively high, the accumulation effect and lateral expansion of carriers are limited, thereby effectively reducing the phenomenon of exciting more high-order modes under the working current and improving the lateral beam quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the semiconductor laser (front cavity surface) of the present invention; Figure 2 It is a schematic diagram of the structure of the semiconductor laser (back cavity surface) of the present invention; Figure 3 A top view of the semiconductor laser of the present invention; Figure 4 A top view of a comparative semiconductor laser; Figure 5 This is a comparison chart of the slow axis divergence angle; Among them: 1. N-side metal layer; 2. substrate; 3. buffer layer; 4. N-side confinement layer; 5. N-side waveguide layer; 6. well layer; 7. P-side waveguide layer; 8. P-side confinement layer; 9. low-doped contact layer; 10. high-doped contact layer; 11. carrier confinement region metal layer; 12. P-side electrode metal layer; 13. insulating layer; 14. deep trench structure; 15. carrier confinement region. DETAILED DESCRIPTION

[0026] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings, but is not limited thereto. Example 1

[0027] A semiconductor laser with carrier confinement function, which is divided into a front cavity surface part and a back cavity surface part. The front cavity surface part is respectively composed of an N-face metal layer, a substrate, a buffer layer, an N-face confinement layer, an N-face waveguide layer, a well layer, a P-face waveguide layer, and a P-face confinement layer from bottom to top. Low-doped contact layers are arranged at both ends above the P-face confinement layer. A high-doped contact layer is arranged above the P-face confinement layer between the low-doped contact layers at both ends. The thickness of the high-doped contact layer is greater than that of the low-doped contact layer. Carrier confinement region metal layers are arranged above the low-doped contact layers at both ends. P-face electrode metal layers are arranged on the side between the high-doped contact layer and the carrier confinement region metal layer and above the high-doped contact layer. In the front cavity surface part, the doping concentration of the low-doped contact layer is 1×10 15 Pieces / cm -3 The doping concentration of the high-doped contact layer in the front cavity surface and the back cavity surface is 1×10 20 Pieces / cm -3 .

[0028] The back cavity surface part is respectively N-face metal layer, substrate, buffer layer, N-face confinement layer, N-face waveguide layer, well layer, P-face waveguide layer, and P-face confinement layer from bottom to top. A high-doped contact layer is arranged above the P-face confinement layer. The high-doped contact layer is a convex layer with high middle and low sides. The high middle part of the high-doped contact layer of the back cavity surface forms a ridge with the high-doped contact layer of the front cavity surface. In the back cavity surface part, grooves are etched downward on both sides of the ridge, and the bottom of the groove is in the P-face waveguide layer. An insulating layer is arranged above the high-doped contact layer on both sides of the ridge, on the sidewall of the ridge, and at both ends of the top surface of the ridge. A P-face electrode metal layer is arranged above the insulating layer and the high-doped contact layer not covered by the insulating layer. In the back cavity surface part, the cross-sectional shape of the groove is a trapezoid, with the short side at the bottom.

[0029] The width of the high-doped contact layer in the front cavity surface part and the back cavity surface part is the same, and the top surfaces of the two are located in the same horizontal plane, forming a ridge with a width of 150 μm and a length of 3000 μm.

[0030] The trench etching depth is 150 nm, the width of the short side of the trench is 8 μm, and the distance between the two side edges of the short side of the trench and the ridge is 30 μm.

[0031] The P-side electrode metal layer is Ti / Pt / Au, and the thickness of the P-side electrode metal layer is 30nm / 50 / nm / 100nm.

[0032] The N-side metal layer is Ni / Ge / Au, and the thickness of the N-side metal layer is 20nm / 50nm / 100nm.

[0033] The insulating layer is SiO2, the metal layer in the carrier confinement region is a metal-semiconductor structure, the metal is a Ni / Au bimetallic structure with a thickness of 30nm / 100nm, and the semiconductor has a doping concentration less than or equal to 1×10 17 Pieces / cm-3 The length of the carrier confinement region (Schottky contact structure) is 200 μm, that is, Figure 3 15 indicates the length in the vertical direction; the thickness after thinning is 130 μm, the high temperature annealing temperature is 450° C., the annealing time is 2 min, and the annealing atmosphere is nitrogen. Example 2

[0034] A semiconductor laser with carrier confinement effect, the structure of which is as described in Example 1, except that the doping concentration of the low-doped contact layer is 1×10 17 Pieces / cm -3 The doping concentration of the highly doped contact layer is 1×10 20 Pieces / cm -3 ; The ridge width is 150μm, the ridge length is 4000μm, and the corrosion depth is 150nm; the short side width of the groove is 8μm, and the distance between the two side edges of the short side of the groove and the ridge is 30μm; the P-side electrode metal layer is Ti / Pt / Au, and the thickness is 20nm / 50 / nm / 300nm; the carrier confinement region (Schottky contact structure) is 300μm long, and the metal of the carrier confinement region is Ni / Pt / Au multi-metal structure, and the thickness is 10nm / 40 / nm / 200nm; the back N-side metal layer electrode structure is Ni / Ge / Au, and the thickness of the N-side electrode metal layer is 20nm / 40nm / 80nm; the thickness after thinning is 130μm, the high temperature annealing temperature is 450℃, the annealing time is 2min, and the annealing atmosphere is nitrogen. Example 3

[0035] A semiconductor laser with carrier confinement effect, the structure of which is as described in Example 1, except that the doping concentration of the low-doped contact layer is 1×10 14 Pieces / cm -3 The doping concentration of the high-doped contact layer in the front cavity surface and the back cavity surface is 1×10 18 Pieces / cm -3 The width of the ridge is 100 μm, and the length of the ridge is 1000 μm. The groove etching depth is 100 nm, the width of the short side of the groove is 5 μm, and the distance between the two sides of the short side of the groove and the ridge is 20 μm.

[0036] The P-side electrode metal layer is Ti / Cr / Au with a thickness of 10nm / 10nm / 100nm. The N-side metal layer is Ni / Ti / Au with a thickness of 10nm / 10nm / 50nm.

[0037] The length of the carrier confinement region (Schottky contact structure) is 100 μm.

[0038] The thickness after thinning is 120 μm, the high temperature annealing temperature is 400° C., the annealing time is 1 min, and the annealing atmosphere is nitrogen. Example 4

[0039] A semiconductor laser with carrier confinement effect, the structure of which is as described in Example 1, except that the doping concentration of the low-doped contact layer is 1×10 17 Pieces / cm -3 The doping concentration of the high-doped contact layer in the front cavity surface and the back cavity surface is 1×10 20 Pieces / cm -3 The ridge width is 200 μm, and the ridge length is 5000 μm. The trench etching depth is 200 nm, the trench short side width is 10 μm, and the distance between the two side edges of the trench short side and the ridge is 50 μm.

[0040] The P-side electrode metal layer is Ti / Ag / Au with a thickness of 100nm / 100nm / 500nm. The N-side metal layer is Ni / V / Au with a thickness of 100nm / 100nm / 300nm.

[0041] The length of the carrier confinement region (Schottky contact structure) is 400μm.

[0042] The thickness after thinning is 150 μm, the high temperature annealing temperature is 500° C., the annealing time is 3 min, and the annealing atmosphere is nitrogen. Example 5

[0043] A method for preparing the semiconductor laser with carrier confinement effect described in Example 1 comprises the following steps: (1) Growth of epitaxial layers with different doping concentrations, where the epitaxial layers include a contact layer, a confinement layer, a waveguide layer, and a well layer, wherein the contact layer is made of materials with different doping concentrations.

[0044] The contact layer is made of GaAs semiconductor material; it is divided into a low-doped contact layer and a high-doped contact layer according to different doping concentrations; and Mg doping is used for doping.

[0045] (2) Ridge stripe preparation: the ridge stripe is prepared by wet etching, and the wet etching is chemical etching in an acidic solution.

[0046] (3) Groove preparation: Grooves are arranged on both sides of the ridge to limit the beam path, reduce the scattering of the beam during propagation, improve the beam quality, and isolate the current. The width of the short side of the groove is 5 μm-10 μm, and the etching depth reaches the P-side waveguide layer; the distance between the edges of the short side of the groove and the ridge is 20 μm-50 μm.

[0047] (4) Insulating layer growth: Insulating layer growth is performed by PECVD to prevent current leakage under the laser operating current; the insulating layer is SiO2.

[0048] (5) Preparation of the P-side electrode metal layer: The P-side electrode metal layer is prepared by electron beam evaporation and the pattern is prepared by a lift-off process. The P-side electrode metal layer area is a highly doped area of ​​the contact layer and is lift-off-processed by negative photoresist.

[0049] (6) Preparation of the metal layer in the carrier confinement area. The contact layer in the carrier confinement area is a low-doped contact layer. In order to further confine the carriers, increase the barrier height, and reduce the tunneling effect, a Schottky contact structure is prepared.

[0050] The Schottky contact structure (i.e., the carrier confinement region) has a length of 100 μm to 400 μm, and the length direction is the length direction between the front cavity surface and the rear cavity surface (i.e., Figure 3 The vertical length in the middle), its structure is a metal-semiconductor structure, and the metal is prepared by electron beam evaporation.

[0051] (7) Preparation of the back electrode: thinning and metal evaporation of the back side of the epitaxial wafer. The back side is thinned so that the thickness of the metal layer from the N-side metal layer to the P-side electrode of the entire wafer is 120μm-150μm. The back side N-side metal layer electrode is prepared by electron beam evaporation.

[0052] (8) The semiconductor laser is subjected to rapid high temperature annealing at a temperature of 400°C-500°C, an annealing time of 1-3 minutes, and an annealing atmosphere of nitrogen.

[0053] Comparative Example 1

[0054] Prepare a semiconductor laser with no carrier confinement region, the front cavity surface and the back cavity surface have the same structure, as shown in Figure 4 shown.

[0055] The tube cores of Examples 1, 2 and Comparative Example 1 were packaged onto a COS heat sink, and the samples were tested at room temperature under a continuous operating current of 25A. 15 COS samples were selected for each sample as the average test data and subjected to a 30A aging test. The test data are shown in the following table.

[0056] Table 1 Test data

[0057] From the COD, aging conditions and divergence angles of the embodiment and the comparative example, it can be seen that the COD current of the embodiment is close to 100A, while the comparative example is only 60A. After the same aging time, there is no failure COS in the embodiment, and the failure rate of the comparative example is 20%. From the divergence angle diagram, it can be seen that the horizontal divergence angle of the embodiment is smaller than that of the comparative example, the divergence angle of the embodiment is 8-8.5 degrees (95% energy), and the comparative example is 10.5 degrees (95% energy). It can be seen from the above data that the present invention effectively improves the COD current, has good reliability, and improves the quality of the light spot.

Claims

1. A semiconductor laser having a carrier confinement effect, characterized in that: It is divided into a front cavity surface part and a back cavity surface part. The front cavity surface part comprises, from bottom to top, an N-face metal layer, a substrate, a buffer layer, an N-face confinement layer, an N-face waveguide layer, a well layer, a P-face waveguide layer, and a P-face confinement layer. Low-doped contact layers are arranged at both ends above the P-face confinement layer. A high-doped contact layer is arranged above the P-face confinement layer between the low-doped contact layers at both ends. The thickness of the high-doped contact layer is greater than that of the low-doped contact layer. Carrier confinement region metal layers are arranged above the low-doped contact layers at both ends. P-face electrode metal layers are arranged on the side between the high-doped contact layer and the carrier confinement region metal layer and above the high-doped contact layer. The back cavity surface part is respectively composed of N-face metal layer, substrate, buffer layer, N-face confinement layer, N-face waveguide layer, well layer, P-face waveguide layer and P-face confinement layer from bottom to top. A high-doped contact layer is arranged above the P-face confinement layer. The high-doped contact layer is a convex layer with high middle and low sides. The high middle part of the high-doped contact layer of the back cavity surface forms a ridge with the high-doped contact layer of the front cavity surface. In the back cavity surface part, grooves are etched downward on both sides of the ridge, and the bottom of the groove is in the P-face waveguide layer. An insulating layer is arranged above the high-doped contact layer on both sides of the ridge, on the side walls of the ridge, and at both ends of the top surface of the ridge. A P-face electrode metal layer is arranged above the insulating layer and the high-doped contact layer not covered by the insulating layer.

2. The semiconductor laser with carrier confinement effect according to claim 1, characterized in that: In the rear cavity surface part, the cross-sectional shape of the groove is a trapezoid, with the short side at the bottom.

3. The semiconductor laser with carrier confinement effect according to claim 1, characterized in that: In the front cavity surface part, the doping concentration of the low-doped contact layer is 1×10 14 -1×10 17 Pieces / cm -3 The doping concentration of the high-doped contact layer in the front cavity surface and the back cavity surface is 1×10 18 -1×10 20 Pieces / cm -3 .

4. The semiconductor laser with carrier confinement function according to claim 1, characterized in that: The high-doped contact layers in the front cavity surface part and the back cavity surface part have the same width, and the top surfaces of the two are located in the same horizontal plane, forming a ridge with a width of 100μm-200μm and a length of 1000μm-5000μm.

5. The semiconductor laser with carrier confinement function according to claim 1, characterized in that: The trench etching depth is 100nm-200nm, the trench short side width is 5μm-10μm, and the distance between the two side edges of the trench short side and the ridge is 20μm-50μm.

6. The semiconductor laser with carrier confinement function according to claim 1, characterized in that: The P-side electrode metal layer is Ti / Pt / Au or Ti / Cr / Au or Ti / Ag / Au; the N-side metal layer is Ni / Ge / Au or Ni / Ti / Au or Ni / V / Au.

7. The semiconductor laser with carrier confinement function according to claim 6, characterized in that: The thickness of the P-side electrode metal layer is 10nm-100nm / 10nm-100nm / 100nm-500nm, and the thickness of the N-side metal layer is 10nm-100nm / 10nm-100nm / 50nm-300nm.

8. The semiconductor laser with carrier confinement function according to claim 1, characterized in that: The insulating layer is SiO2, the metal layer in the carrier confinement region is a metal-semiconductor structure, the metal is selected from Ni, Au, Al, Pt, and the semiconductor is doped with a concentration less than or equal to 1×10 17 Pieces / cm -3 Low-doped GaAs, the carrier confinement region length is 100μm-400μm.

9. A method for preparing a semiconductor laser having a carrier confinement effect, characterized in that: The following steps are involved: (1) Growth of epitaxial layers with different doping concentrations, where the epitaxial layers include a contact layer, a confinement layer, a waveguide layer, and a well layer, wherein the contact layer is made of materials with different doping concentrations; (2) Ridge stripe preparation: the ridge stripe is prepared by wet etching, wherein the wet etching is chemical etching in an acidic solution, and the wet etching obtains the ridge stripe width of 100 μm-200 μm, the ridge stripe length of 1000 μm-5000 μm, and the etching depth of 100 nm-200 nm; (3) Groove preparation, where the grooves are arranged on both sides of the ridge strip, the width of the short side of the groove is 5 μm-10 μm, and the etching depth reaches the P-side waveguide layer; the distance between the two side edges of the short side of the groove and the ridge strip is 20 μm-50 μm; (4) Insulating layer growth: Insulating layer growth is performed by PECVD, and the insulating layer is SiO2; (5) Preparation of the P-side electrode metal layer: The P-side electrode metal layer is prepared by electron beam evaporation and the pattern is prepared by lift-off process; (6) Preparation of a metal layer in the carrier confinement region, wherein the contact layer in the carrier confinement region is a low-doped contact layer, and a Schottky contact structure is prepared; (7) Preparation of back electrode: thinning and metal evaporation of the back side of the epitaxial wafer. The back side is thinned so that the thickness of the metal layer from the N-side metal layer to the P-side electrode of the entire wafer is 120 μm-150 μm. Electron beam evaporation is used to prepare the back side metal layer electrode; (8) The semiconductor laser is subjected to high temperature annealing at a temperature of 400°C to 500°C, an annealing time of 1 to 3 minutes, and an annealing atmosphere of nitrogen.

10. The method for preparing a semiconductor laser with carrier confinement function according to claim 9, characterized in that: In step (1), the contact layer is made of GaAs semiconductor material; it is divided into a low-doped contact layer and a high-doped contact layer according to different doping concentrations; Mg doping is used, wherein the doping concentration of the low-doped contact layer is 1×10 14 -1×10 17 Pieces / cm -3 The doping concentration of the highly doped contact layer is 1×10 18 -1×10 20 Pieces / cm -3 ; In step (6), the length of the Schottky contact structure, i.e., the carrier confinement region, is 100 μm-400 μm, the length direction is the length direction of the front cavity surface and the rear cavity surface, and the structure is a metal-semiconductor structure, and the metal is prepared by electron beam evaporation.

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