阅读说明：本技术 一种偏脊结构带有焊线图形的半导体激光器的制备方法 (Preparation method of semiconductor laser with ridge structure and bonding wire pattern ) 是由 王金翠 刘青 苏建 陈康 任夫洋 于 2018-07-27 设计创作，主要内容包括：一种偏脊结构带有焊线图形的半导体激光器的制备方法。制备的肩部Ⅰ与肩部Ⅱ不等宽,使脊型结构不在位于芯片的正中间,在较宽的肩部Ⅱ上可以有充裕的空间先设置好金丝焊线位置图形,后其在金丝焊线位置图形上进行金丝打线就有效避免了损伤管芯的情况发生,有效避免金丝打线时造成管芯坏死或者失效的情况发生。同时由于在脊型结构上制备了电流注入窗口,即标记了出光面,便于后续封装。由于在较宽的肩部Ⅱ中制备出沟槽Ⅱ,从而避免了由于肩部Ⅱ相对肩部Ⅰ较宽导致电流注入时候不均匀的情况。由于在激光器芯片表面除去金丝焊线位置图形之外的区域生长一层介质膜Ⅱ,因此可以保护芯片不被损伤。(A method for manufacturing a semiconductor laser with a ridge structure and a bonding wire pattern. The prepared shoulder I and the shoulder II are not as wide as each other, so that the ridge structure is not positioned in the middle of the chip, a sufficient space can be reserved on the wide shoulder II, a gold wire bonding position pattern is arranged at first, then gold wire bonding is carried out on the gold wire bonding position pattern, the condition that a tube core is damaged is effectively avoided, and the condition that the tube core is necrotic or fails during gold wire bonding is effectively avoided. Meanwhile, the current injection window is prepared on the ridge structure, namely the light emitting surface is marked, so that subsequent packaging is facilitated. The groove II is prepared in the wider shoulder II, so that the condition that the current injection is uneven due to the fact that the shoulder II is wider than the shoulder I is avoided. Since a dielectric film II grows on the surface of the laser chip except the pattern of the gold wire bonding position, the chip can be protected from being damaged.)

1. A method for preparing a semiconductor laser with a ridge structure and a bonding wire pattern comprises the following steps that a substrate and an epitaxial layer (1) of the semiconductor laser sequentially comprise the substrate, a lower buffer layer, a lower limiting layer, a lower waveguide layer, a quantum well layer, an upper waveguide layer, an upper limiting layer, an upper buffer layer and an ohmic contact layer from bottom to top:

a) etching two grooves I (5) on a substrate and an epitaxial layer (1) by using a photoetching mask through the processes of exposure, development and corrosion, forming a raised ridge structure (4) between the two grooves I (5), forming a shoulder I (2) and a shoulder II (3) on the outer sides of the two grooves I (5) respectively, wherein the width of the shoulder II (3) is greater than that of the shoulder I (2);

b) etching a groove II (8) in the shoulder II (3) by utilizing a photoetching mask through the processes of exposure, development and corrosion, dividing the shoulder II (3) into a left part and a right part by the groove II (8), and matching the width of the divided shoulder II (3) positioned on the inner side with the width of the ridge-shaped structure (4);

c) growing a dielectric film I (6) on the outer surfaces of the shoulder I (2), the ridge structure (4) and the shoulder II (3), and preparing a current injection window (10) on the dielectric film I (6) on the upper end surface of the ridge structure (4) through a photoetching machine corrosion process;

d) growing a P-surface electrode (7) on the surface of the dielectric film I (6);

e) preparing a gold wire bonding position pattern (9) on the upper end face of the shoulder part II (3) at two sides of the groove II (8), and taking the gold wire bonding position pattern (9) as a gold wire routing position;

f) and growing a dielectric film II (11) on the upper surface of the P-face electrode (7) except for the gold wire bonding position pattern (9).

2. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: the etching process in the step a) is wet etching or dry etching.

3. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: the thickness of the dielectric film I (6) in step c) is 1000A to 2000A.

4. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: in the step a), the width and the depth of the two grooves I (5) are equal.

5. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: the distance between the groove II (8) and the ridge structure (4) is equal to the width of the shoulder I (2), and the difference between the width of the groove II (8) and the width of the groove I (5) is less than or equal to 30%.

6. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: the width of the position pattern (9) of the wire bonding wire in the step e) is more than 90 um.

7. The method of claim 1 wherein the ridge structure comprises a semiconductor laser with a wire bond pattern, the method comprising: step f) preparation of the medium film II (11) from

Technical Field

The invention relates to the technical field of semiconductor lasers, in particular to a preparation method of a semiconductor laser with a ridge structure and a bonding wire pattern.

Background

Since the advent, semiconductor lasers have been favored as a new type of light source in the fields of optical storage, optical communication, national defense, medical care, and the like because of their advantages such as small size, high power, long life, and convenience in use. The ridge waveguide laser is used as a common semiconductor laser, and becomes an important and dominant product with the advantages of simple manufacturing process, good repeatability, stable product parameters and the like.

When the semiconductor chip is required to emit light, an electric signal for driving the chip to emit light needs to be obtained from the outside, and the semiconductor chip needs to be connected with an external connector through a connecting wire such as a gold wire, so that a wire bonding operation needs to be performed on the surface of the chip. The basic structure of a typical ridge waveguide type semiconductor chip is shown in fig. 1, where the ridge of the laser is located on the surface of the semiconductor chip, and the portions on both sides of the ridge structure can be used as the positions of electrode pads. However, with the development of the integration technology, the requirement for the chip size is smaller and smaller, and the chip size is smaller, so that the sizes of both sides of the ridge structure on the chip are reduced, a bonding pad of a gold wire bonding is easily bonded on the ridge structure during the wire bonding operation, so that the chip is damaged or failed, and the like.

Chinese patent CN100459067C provides an electrode pad on a semiconductor substrate that reduces the capacitance of an electrode pad portion while enabling characteristic impedance control for practical electrode pad sizes. An n-InP substrate is provided with an n-InP cladding layer, an i layer, a P-InP cladding layer, and a P-type contact layer, and a mesa stripe type optical waveguide is formed by laminating the n-InP cladding layer, the i layer, the P-InP cladding layer, and the P-type contact layer. The patent mainly teaches to reduce the capacitance of an electrode pad formed on a conductive semiconductor substrate, and to specially prepare a mesa-shaped deposition portion for disposing the electrode pad.

Chinese patent CN100459331C teaches an asymmetric ridge waveguide GaN-based semiconductor laser, which uses an etching method to form an asymmetric ridge waveguide GaN-based laser in the direction parallel to the junction, and this structure can also realize the laser working under the basement membrane when the ridge width is large, and the allowable ridge width is large, and the injected current can be increased under the condition that the re-injected current density is the same, so as to improve the output power of the laser when the basement membrane is working. The patent mainly teaches that the ridge structure of the GaN-based laser is itself asymmetric in shape with its P, N electrode on the same side of the chip.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the preparation method of the semiconductor laser with the bonding wire pattern in the ridge structure, which avoids damaging the tube core during gold wire bonding and avoids the difference of the bonding positions between the tube core and the tube core.

The technical scheme adopted by the invention for overcoming the technical problems is as follows:

a method for preparing a semiconductor laser with a ridge structure and a bonding wire pattern comprises the following steps that a substrate and an epitaxial layer of the semiconductor laser sequentially comprise the substrate, a lower buffer layer, a lower limiting layer, a lower waveguide layer, a quantum well layer, an upper waveguide layer, an upper limiting layer, an upper buffer layer and an ohmic contact layer from bottom to top:

a) etching two grooves I on a substrate and an epitaxial layer by utilizing a photoetching mask through the processes of exposure, development and corrosion, forming a raised ridge structure between the two grooves I, respectively forming a shoulder I and a shoulder II on the outer sides of the two grooves I, wherein the width of the shoulder II is greater than that of the shoulder I;

b) etching a groove II in the shoulder II by utilizing the photoetching mask through the processes of exposure, development and corrosion, dividing the shoulder II into a left part and a right part by the groove II, and matching the width of the divided shoulder II positioned on the inner side with the width of the ridge structure;

c) growing a dielectric film I on the outer surfaces of the shoulder I, the ridge structure and the shoulder II, and preparing a current injection window on the dielectric film I on the upper end surface of the ridge structure through a photoetching machine corrosion process;

d) growing a P-surface electrode on the surface of the dielectric film I;

e) preparing a gold wire bonding position pattern on the upper end face of the shoulder part II on two sides of the groove II, and taking the gold wire bonding position pattern as a gold wire routing position;

f) and growing a dielectric film II on the upper surface of the P-face electrode except the pattern of the gold wire bonding position.

Preferably, the etching process in step a) is wet etching or dry etching.

Preferably, the thickness of the dielectric film I in step c) is between 1000A and 2000A.

Preferably, the width and depth of the two trenches i in step a) are equal.

Preferably, the distance between the groove II and the ridge structure is equal to the width of the shoulder I, and the difference between the width of the groove II and the width of the groove I is less than or equal to 30%.

Preferably, the width of the wire bond location pattern in step e) is greater than 90 um.

Preferably, the medium membrane II in step f) consists ofOr

The material is prepared.

The invention has the beneficial effects that: because the prepared shoulder I and the shoulder II are not as wide as each other, the ridge structure is not positioned in the middle of the chip, a sufficient space can be reserved on the wide shoulder II, a gold wire bonding position pattern is arranged at first, then gold wire bonding is carried out on the gold wire bonding position pattern, the condition that a tube core is damaged is effectively avoided, and the condition that the tube core is necrotic or fails during gold wire bonding is effectively avoided. Meanwhile, the current injection window is prepared on the ridge structure, namely the light emitting surface is marked, so that subsequent packaging is facilitated. The groove II is prepared in the wider shoulder II, so that the condition that the current injection is uneven due to the fact that the shoulder II is wider than the shoulder I is avoided. Since a dielectric film II grows on the surface of the laser chip except the pattern of the gold wire bonding position, the chip can be protected from being damaged.

Drawings

FIG. 1 is a schematic cross-sectional view of a conventional laser chip;

FIG. 2 is a schematic cross-sectional view of a laser chip according to the present invention;

in the figure, 1, a substrate and an epitaxial layer 2, a shoulder I3, a shoulder II 4, a ridge structure 5, a groove I6, a dielectric film I7, a P surface electrode 8, a groove II 9, a gold wire bonding position pattern 10, a current injection window 11 and a dielectric film II.

Detailed Description

The invention will be further explained with reference to fig. 1 and 2.

A method for preparing a semiconductor laser with a ridge structure and a bonding wire pattern comprises the following steps that a substrate and an epitaxial layer 1 of the semiconductor laser sequentially comprise the substrate, a lower buffer layer, a lower limiting layer, a lower waveguide layer, a quantum well layer, an upper waveguide layer, an upper limiting layer, an upper buffer layer and an ohmic contact layer from bottom to top:

a) etching two grooves I5 on the substrate and the epitaxial layer 1 by using a photoetching mask through the processes of exposure, development and corrosion, forming a raised ridge structure 4 between the two grooves I5, forming a shoulder I2 and a shoulder II 3 on the outer sides of the two grooves I5 respectively, wherein the width of the shoulder II 3 is greater than that of the shoulder I2;

b) etching a groove II 8 in the shoulder II 3 by utilizing a photoetching mask through the processes of exposure, development and corrosion, wherein the shoulder II 3 is divided into a left part and a right part by the groove II 8, and the width of the divided shoulder II 3 positioned on the inner side is matched with the width of the ridge structure 4;

c) growing a dielectric film I6 on the outer surfaces of the shoulder I2, the ridge structure 4 and the shoulder II 3, and preparing a current injection window 10 on the dielectric film I6 on the upper end surface of the ridge structure 4 through a photoetching machine corrosion process;

d) growing a P-surface electrode 7 on the surface of the dielectric film I6;

e) preparing a gold wire bonding position pattern 9 on the upper end face of the shoulder part II 3 at two sides of the groove II 8, and taking the gold wire bonding position pattern 9 as a gold wire routing position;

f) and a dielectric film II 11 is grown on the upper surface of the P-face electrode 7 except for the region of the gold wire bonding position pattern 9.

Because the prepared shoulder I2 and the shoulder II 3 are not as wide as each other, the ridge structure 4 is not positioned in the middle of the chip, a sufficient space can be reserved on the wide shoulder II 3, a gold wire bonding position pattern is arranged at first, then gold wire routing is carried out on the gold wire bonding position pattern, the condition that the die is damaged is effectively avoided, and the condition that the die is necrotic or fails during gold wire routing is effectively avoided. Meanwhile, the current injection window 10 is prepared on the ridge structure 4, namely the light-emitting surface is marked, so that subsequent packaging is facilitated. Because the groove II 8 is prepared in the wider shoulder II 3, the condition that the current injection is uneven because the shoulder II 3 is wider than the shoulder I2 is avoided. Since a dielectric film II 11 is grown on the surface of the laser chip except the region of the gold wire bonding position pattern 9, the chip can be protected from being damaged.