Laser chip coating method and laser chip
By forming a pre-covered film on the cavity surface and electrode surface of the laser chip, and plating an optical film on the basis of the film, the problem of the optical film falling off on the cavity surface and electrode of the laser chip is solved, and the film layer is improved Adhesion and stability during packaging.
Patent Information
- Application Number
- CN202411245659.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2044-09-06
AI Technical Summary
When the optical film is plated on the cavity surface of the laser chip, due to the difference in width between the laser chip and the strap, the optical film layer is prone to fall off on the cavity surface, front and back metal electrodes of the laser chip, resulting in poor adhesion and damage to the film layer and solder overflow.
The pre-covered film is grown on the cavity surface of the laser chip, and the pre-covered film is plated onto the P-side electrode and the N-side electrode to form a pre-covered film, and then the pre-covered film on the cavity surface is removed to retain the film on the electrode. , and then the optical film is plated on the cavity surface and plating onto the pre-covered film to form an optical film.
By increasing the adhesion between the optical film and the pre-covered film and the metal electrode surface, the optical film is prevented from falling off and contaminating the cavity surface, and preventing solder spillage during the packaging process, ensuring the stability and quality of the film layer.
Smart Images
Figure CN118763497B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor laser technology, and in particular to a laser chip coating method and a laser chip. Background Art
[0002] When the laser chip is coated with an optical film on the cavity surface, due to the width difference between the laser chip and the accompanying strip, that is, the laser chip is wide and the accompanying strip is narrow, the optical film layer is not only coated on the cavity surface of the laser chip, but also on the metal electrodes on the front and back of the laser chip, forming an optical film flip. Therefore, there are multiple problems as follows:
[0003] (1) If Figure 1 As shown in the figure, the adhesion between the optical film and the metal electrodes on the front and back sides of the laser chip is poor, which causes the optical film layer to easily fall off to the cavity surface of the laser chip, causing debris contamination on the cavity surface;
[0004] (2) When the optical film is flipped off, the edge of the optical film formed by the flipped film and the cavity surface is torn, resulting in damage to the edge of the cavity surface optical film, affecting the quality of the cavity surface optical film;
[0005] (3) The optical film is formed on the metal electrodes on the front and back of the laser chip. When the laser chip is packaged and mounted, it can block the solder and prevent the solder from overflowing onto the cavity surface of the laser chip and causing damage to the cavity surface. However, after the optical film is removed, it loses its blocking effect on the solder. Summary of the invention
[0006] The present invention provides a laser chip coating method and a laser chip, and the specific scheme is as follows.
[0007] A laser chip coating method, the method comprising:
[0008] Growing a pre-covering film on the cavity surface of the laser chip, and plating the pre-covering film around the P-side electrode and the N-side electrode of the laser chip to form a pre-covering film flipping film;
[0009] Removing the pre-covering film grown on the cavity surface of the laser chip, and retaining the pre-covering film formed on the P-surface electrode and the N-surface electrode;
[0010] An optical film is plated on the cavity surface of the laser chip, and the optical film is plated around the pre-covering film to form an optical film.
[0011] Preferably, the width of the pre-covering film is W 1 , the width of the optical film is W 2 , W 2 ≤W 1 .
[0012] Preferably, before growing a pre-covering film on the cavity surface of the laser chip and plating the pre-covering film around the P-surface electrode and the N-surface electrode of the laser chip to form a pre-covering film flipping film, the method further comprises:
[0013] Performing nitridation pretreatment on the cavity surface of the laser chip;
[0014] The laser chip after the nitridation treatment is subjected to low temperature annealing treatment.
[0015] Preferably, after removing the pre-covering film grown on the cavity surface of the laser chip, the method further comprises:
[0016] The cavity surface of the laser chip from which the pre-covering film has been removed is subjected to nitridation treatment.
[0017] Preferably, after coating an optical film on the cavity surface of the laser chip and coating the optical film around the pre-covering film to form an optical film flipping film, the method further comprises: annealing the laser chip.
[0018] Preferably, the material of the pre-covering film includes at least one of titanium dioxide, nickel oxide or titanium-nickel alloy oxide.
[0019] Preferably, removing the pre-covering film grown on the cavity surface of the laser chip comprises:
[0020] decomposing the pre-covering film using hydrogen plasma;
[0021] The decomposed pre-capping film is removed using argon plasma.
[0022] Preferably, before growing a pre-covering film on the cavity surface of the laser chip and plating the pre-covering film around the P-side electrode and the N-side electrode of the laser chip to form the pre-covering film, the method further comprises: providing a companion bar, arranging and stacking the laser chip and the companion bar, wherein the width difference D between the laser chip and the companion bar is 1 Not less than the width W of the pre-covering film 1 ; and / or, removing the pre-covering film grown on the cavity surface of the laser chip, retaining the pre-covering film formed on the P-side electrode and the N-side electrode before turning over the film, the method also includes: arranging and stacking the laser chip and the accompanying strip, the width of the laser chip is not greater than the width of the accompanying strip.
[0023] Preferably, an optical film is plated on the cavity surface of the laser chip, and the optical film is plated around the pre-covering film. Before forming the optical film, the method further comprises: arranging and stacking the laser chip and the accompanying strip, wherein the width difference D between the laser chip and the accompanying strip is 2 Not less than the width W of the optical film flip film 2 .
[0024] A laser chip is provided with a film layer coated on the laser chip, wherein the film layer is obtained by using the film coating method for a laser chip as described in any one of the above items.
[0025] The present invention provides a laser chip coating method, which has the following technical effects:
[0026] (1) Before coating the laser chip with an optical film, the present invention firstly coats a pre-covering film having good adhesion to the electrode surface on the cavity surface of the laser chip and the surfaces of the P-side electrode and the N-side electrode. On this basis, the laser chip is then coated with an optical film, and the laser chip is annealed to increase the adhesion of the optical film, the pre-covering film and the front and back metal electrode surfaces. Finally, both layers of film can exist stably, thus avoiding the problem of the optical film falling off the metal electrode surface and contaminating the cavity surface in the prior art. In addition, in the subsequent packaging process of the laser chip, the solder can be blocked from overflowing to prevent the solder from contaminating the cavity surface.
[0027] (2) In the present invention, the optical film is coated after the pre-covering film on the cavity surface of the laser chip is removed. The optical film does not need to be removed after coating, so the optical film can be completely adhered to the cavity surface. Compared with the prior art, this can prevent the edge of the optical film on the cavity surface from being torn when the optical film falls off from the front or back side, thereby preventing the quality of the cavity surface film from being affected. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0029] Figure 1 It is a figure showing that the optical film on the P-side electrode and the N-side electrode of the laser chip in the prior art is flipped and peeled off to the cavity surface;
[0030] Figure 2 It is a schematic diagram of the pre-covering film and the pre-covering film flipping formed on the cavity surface, P-side electrode and N-side electrode of the laser chip after the pre-covering film is plated on the laser chip in step 1 of the first embodiment;
[0031] Figure 3 This is a schematic diagram of arranging and stacking the laser bars and companion bars in step 1 of the second embodiment;
[0032] Figure 4 This is a schematic diagram of arranging and stacking the laser bars and companion bars in step 2 of the second embodiment;
[0033] Figure 5 This is a schematic diagram of arranging and stacking the laser bars and companion bars in step 3 of the second embodiment;
[0034] Figure 6 The figure is a schematic flow chart of a coating method for a laser chip according to the first embodiment of the present invention.
[0035] In the figure, 1. cavity surface, 2. optical film debris, 3. laser chip, 4. companion strip, 5. pre-covering film flipping, 6. pre-covering film, 7. laser bar. DETAILED DESCRIPTION
[0036] The technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0037] Embodiment 1
[0038] like Figure 6 As shown, an embodiment of the present invention provides a coating method for a laser chip, comprising:
[0039] Step 1, growing a pre-covering film on the cavity surface 1 of the laser chip 3, and coating the pre-covering film on the P-surface electrode and the N-surface electrode of the laser chip 3 to form a pre-covering film flipping film 5;
[0040] Step 2, removing the pre-covering film 6 grown on the cavity surface of the laser chip 3, and retaining the pre-covering film flipping film 5 formed on the P-surface electrode and the N-surface electrode of the laser chip 3;
[0041] Step 3, forming an optical film on the cavity surface of the laser chip 3, and coating the optical film on the pre-covering film 5 to form an optical film folding film.
[0042] After the laser chip is plated with a pre-covering film, a pre-covering film and a pre-covering film flipping diagram are formed on the cavity surface, the P-side electrode and the N-side electrode of the laser chip. Figure 2 shown.
[0043] Preferably, the width of the pre-covering film 5 is W 1 , the width of the optical film is W 2 , W 2 ≤W 1 .
[0044] In step 1, before growing a pre-covering film 6 on the cavity surface 1 of the laser chip 3 and plating the pre-covering film around the P-surface electrode and the N-surface electrode of the laser chip 3 to form a pre-covering film turning film 5, the step further includes:
[0045] Performing nitridation pretreatment on the cavity surface 1 of the laser chip 3;
[0046] The laser chip 3 after the nitridation treatment is subjected to a low temperature annealing treatment.
[0047] Before growing the pre-covering film layer, the cavity surface 1 of the laser chip 3 is nitrided by nitrogen plasma to eliminate the dangling bonds on the cavity surface and form a nitride film. The presence of the nitride film has the following advantages: (1) The nitride film is unstable and is easy to desorb after high-temperature treatment or ion bombardment, which is beneficial to the removal of the pre-covering film layer in the next step; (2) The presence of the nitride film can provide preliminary protection for the cavity surface 1 to prevent the subsequent pre-covering film from directly contacting and reacting with the substrate during growth; (3) In the process of removing the pre-covering film in the next step, the presence of the nitride film can protect the cavity surface 1 to prevent damage to the substrate during the removal process; (4) The nitride itself can passivate the cavity surface 1. Even if some nitride remains on the cavity surface 1, it will not affect the performance of the laser chip 3.
[0048] The low-temperature annealing treatment of the laser chip 3 has little effect on the nitride film that has been bonded to the cavity surface 1 of the laser chip 3, but it can desorb the nitrogen atoms adsorbed on the surface of the P-side metal electrode and the N-side metal electrode during the nitridation step of the cavity surface 1 from the electrode surface, so as to ensure that the pre-covering film grown in the next step is not affected by the nitridation of the cavity surface in step 2.
[0049] In step 2, removing the pre-covering film 6 grown on the cavity surface 1 of the laser chip 3 includes:
[0050] The pre-covering film 6 grown on the cavity surface 1 is decomposed by hydrogen plasma, and the decomposed pre-covering film 6 is removed by argon plasma.
[0051] After removing the pre-covering film 6 grown on the cavity surface 1 of the laser chip 3, the method further includes: performing nitridation treatment on the cavity surface 1 of the laser chip 3 from which the pre-covering film 6 has been removed to form a nitride film again. Even if the nitride film on the cavity surface 1 is damaged in the process of removing the pre-covering film layer in the previous step, a nitride film can be formed on the cavity surface 1 again.
[0052] In step 3, after an optical film is plated on the cavity surface 1 of the laser chip 3 and the optical film is coiled onto the pre-covering film 5 to form an optical film coil, the step also includes: annealing the laser chip 3 to increase the adhesion between the coiled optical film and the coiled pre-covering film layer on the surface of the P-side electrode and the N-side electrode to prevent the coiled optical film from falling off.
[0053] Preferably, the material of the pre-covering film includes at least one of titanium dioxide, nickel oxide or titanium-nickel alloy oxide. The metal components of the front and back electrodes of the laser chip 3 mainly include gold, nickel, titanium, etc. Therefore, the selection of the pre-covering film material mainly reacts with the metal elements in the electrode metal layer. Titanium dioxide, nickel oxide or titanium-nickel alloy oxide is selected as the material of the pre-covering film. On the one hand, it is the same as the main element on the surface of the electrode metal, and no other metal elements are introduced; on the other hand, an oxide film is selected. Since oxygen has a large electronegativity, it is easy to form a stable chemical bond with the metal element, thereby improving the adhesion between the pre-covering film and the metal electrode surface.
[0054] Preferably, the laser chip includes but is not limited to a laser bar and a laser single tube.
[0055] It should be understood that the metal electrodes described in this application include P-side electrodes and / or N-side electrodes; the P-side electrode, positive electrode and P-side metal electrode are all the same concept, and the N-side electrode, negative electrode and negative metal electrode are all the same concept.
[0056] Embodiment 2
[0057] An embodiment of the present invention provides a coating method for a laser chip, wherein the laser chip is a laser bar. In this embodiment, the laser bar 7 is coated by arranging and stacking the laser bar 7 and the companion bar 4 .
[0058] The method for coating a laser bar by arranging and stacking a laser bar and a companion bar comprises the following steps: Step 1, arranging and stacking the laser bar 7 and the companion bar 4 for the first time, as shown in the attached figure. Figure 3 As shown, the width difference D between the laser bar 7 and the companion bar 4 is 1 Not less than the width W of the pre-covering film 5 1 ; growing a pre-covering film on the cavity surface 1 of the laser bar 7, and plating the pre-covering film around the P-side electrode and N-side electrode of the laser bar 7 to form a pre-covering film flipping film 5; disassembling the arrangement of the laser bar 7 and the accompanying bar 4.
[0059] Step 2, arrange and stack the laser bar 7 and the companion bar 4 for the second time, the width of the laser bar 7 is not greater than the width of the companion bar 4, such as Figure 4 As shown; a pre-covering film is grown on the cavity surface 1 of the laser bar 7, and the pre-covering film is plated around the P-side electrode and the N-side electrode of the laser bar 7 to form a pre-covering film flip film 5; the arrangement of the laser bar 7 and the accompanying bar 4 is disassembled.
[0060] Step 3: Arrange and stack the laser bar 7 and the companion bar 4 for the third time. The width difference D between the laser bar 7 and the companion bar 4 is 2 Not less than the width W of the optical film flip 1 ,like Figure 5As shown; an optical film is coated on the cavity surface 1 of the laser bar 7, and the optical film is coated around the pre-covering film 5 to form an optical film folding film; the arrangement of the laser bar 7 and the accompanying bar 4 is disassembled.
[0061] Preferably, in step 1, before growing a pre-covering film 6 on the cavity surface 1 of the laser bar 7 and plating the pre-covering film around the P-side electrode and the N-side electrode of the laser bar 7 to form a pre-covering film flipping film 5, the method further comprises:
[0062] Performing nitridation pretreatment on the cavity surface 1 of the laser bar 7;
[0063] The laser bar 7 after the nitridation treatment is subjected to a low temperature annealing treatment.
[0064] Preferably, in step 2, removing the pre-covering film 6 grown on the cavity surface 1 of the laser bar 7 comprises:
[0065] The pre-covering film 6 grown on the cavity surface 1 is decomposed by hydrogen plasma, and the decomposed pre-covering film 6 is removed by argon plasma.
[0066] Preferably, after removing the pre-covering film 6 grown on the cavity surface 1 of the laser bar 7, the method further includes: performing nitridation treatment on the cavity surface 1 of the laser bar 7 from which the pre-covering film 6 is removed to form a nitride film again. Even if the nitride film on the cavity surface 1 is damaged in the process of removing the pre-covering film layer in the previous step, a nitride film can be formed on the cavity surface 1 again.
[0067] Preferably, in step 3, after an optical film is plated on the cavity surface 1 of the laser bar 7 and the optical film is coiled onto the pre-covering film 5 to form an optical film coil, the step further includes: annealing the laser bar 7 to increase the adhesion between the coiled optical film and the coiled pre-covering film layer on the surface of the P-side electrode and the N-side electrode to prevent the coiled optical film from falling off.
[0068] Preferably, the material of the pre-covering film includes at least one of titanium dioxide, nickel oxide or titanium-nickel alloy oxide.
[0069] It should be understood that the present application does not limit the specific method for coating the laser chip. Those skilled in the art can coat the laser chip by arranging and stacking the laser chips and the companion strips, and can also implement the coating method of the laser chip described in Example 1 through various means such as coating jigs.
[0070] Embodiment 3
[0071] An embodiment of the present invention provides a laser chip, on which a film layer is coated. The film layer is obtained by using the film coating method of the laser chip as described in the first or second embodiment.
[0072] Preferably, the film layer includes: a pre-covering film flipping film formed on the P-side electrode and the N-side electrode of the laser chip; an optical film formed on the cavity surface of the laser chip; and an optical film flipping film formed on the pre-covering film flipping film.
[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A coating method for a laser chip, characterized in that: The method comprises: Growing a pre-covering film on the cavity surface of the laser chip, and plating the pre-covering film around the P-side electrode and the N-side electrode of the laser chip to form a pre-covering film flipping film; Removing the pre-covering film grown on the cavity surface of the laser chip, and retaining the pre-covering film formed on the P-surface electrode and the N-surface electrode; An optical film is plated on the cavity surface of the laser chip, and the optical film is plated around the pre-covering film to form an optical film; the width of the pre-covering film is W1, the width of the optical film is W2, and W2≤W1.
2. A laser chip coating method according to claim 1, characterized in that: Before growing a pre-covering film on the cavity surface of the laser chip and plating the pre-covering film around the P-surface electrode and the N-surface electrode of the laser chip to form a pre-covering film flipping film, the method further includes: Performing nitridation pretreatment on the cavity surface of the laser chip; The laser chip after the nitridation treatment is subjected to low temperature annealing treatment.
3. A laser chip coating method according to claim 2, characterized in that: After removing the pre-covering film grown on the cavity surface of the laser chip, the method further comprises: The cavity surface of the laser chip from which the pre-covering film has been removed is subjected to nitridation treatment.
4. The laser chip coating method according to claim 3, characterized in that: After coating an optical film on the cavity surface of the laser chip and coating the optical film around the pre-covering film to form an optical film flipping film, the method further includes: annealing the laser chip.
5. The laser chip coating method according to claim 4, characterized in that: The material of the pre-covering film includes at least one of titanium dioxide, nickel oxide or titanium-nickel alloy oxide.
6. The laser chip coating method according to claim 5, characterized in that: Removing the pre-covering film grown on the cavity surface of the laser chip, including: decomposing the pre-covering film using hydrogen plasma; The decomposed pre-capping film is removed using argon plasma.
7. A laser chip coating method according to any one of claims 1 to 6, characterized in that: Before growing a pre-covering film on the cavity surface of the laser chip and plating the pre-covering film around the P-side electrode and the N-side electrode of the laser chip to form a pre-covering film flipping film, the method further includes: providing a companion bar, arranging and stacking the laser chip and the companion bar, and the width difference D1 between the laser chip and the companion bar is not less than the width W1 of the pre-covering film flipping film; And / or, removing the pre-covering film grown on the cavity surface of the laser chip, and retaining the pre-covering film formed on the P-side electrode and the N-side electrode before turning over the film, the method also includes: arranging and stacking the laser chip and the companion strip, and the width of the laser chip is not greater than the width of the companion strip.
8. The laser chip coating method according to claim 7, characterized in that: An optical film is plated on the cavity surface of the laser chip, and the optical film is plated around the pre-covering film. Before the optical film is formed, the method further includes: arranging and stacking the laser chip and the accompanying strip, and the width difference D2 between the laser chip and the accompanying strip is not less than the width W2 of the optical film.
9. A laser chip, characterized in that: The laser chip is coated with a film layer, and the film layer is obtained by using the film coating method for a laser chip according to any one of claims 1 to 8.
Citation Information
Patent Citations
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