Method for forming wet oxygen aperture shape of vertical cavity surface emitting laser element

Abstract

A method of forming a wet oxygen aperture shape of a vertical cavity surface emitting laser element includes: placing a vertical cavity surface emitting laser wafer having a circular vertical cavity surface emitting laser mesa having a diameter of 25 [mu] m-30 [mu] m into a wet oxygen furnace; vacuumizing the wet oxygen furnace; heating the wet oxygen furnace to 250-350 DEG C, maintaining the temperature for a first time period, and introducing N2 gas and H2O gas into the wet oxygen furnace in the first time period; n2 gas and H2O gas are continuously introduced into the wet oxygen furnace, and meanwhile, the temperature of the wet oxygen furnace is increased to 350-450 DEG C and maintained for a second time section; n2 gas and H2O gas are continuously introduced into the wet oxygen furnace, and meanwhile, the temperature of the wet oxygen furnace is increased to 400-450 DEG C and maintained for a third time section; maintaining the temperature of the wet oxygen furnace at 400-450 DEG C so as to start to oxidize the vertical cavity surface emitting laser wafer; after oxidation of the vertical cavity surface emitting laser wafer is finished, N2 gas is introduced into the wet oxygen furnace for cooling to 150 DEG C; and taking out the vertical cavity surface emitting laser wafer from the wet oxygen furnace.

Description

Technical Field

[0001] The present invention relates to a vertical cavity surface emitting laser element, and in particular to a method for forming a wet oxygen aperture shape of a vertical cavity surface emitting laser element. Background Art

[0002] In recent years, vertical cavity surface emitting laser (VCSEL) devices have been widely used as light sources in electronic consumer products (eg, virtual reality (VR) sensing devices).

[0003] It is generally known that the wet oxygen aperture shape of the epitaxial layer of the 650nm VCSEL element is diamond-shaped or shield-shaped, and the wet oxygen aperture shape is rarely circular. In the prior art, only the wet oxygen aperture shape of the epitaxial layer of the 940nm VCSEL element is approximately circular. However, due to the essential differences between the epitaxial layer structure and growth characteristics of the 650nm VCSEL element and the 940nm VCSEL element, the wet oxygen aperture shape of the epitaxial layer of the 650nm VCSEL element has not been effectively controlled to be approximately circular like the wet oxygen aperture of the epitaxial layer of the 940nm VCSEL element.

[0004] In view of this, how to form the wet oxygen aperture shape of the epitaxial layer of the 650nm vertical cavity surface emitting laser element into a circular shape is an issue that the industry needs to solve urgently. Summary of the invention

[0005] The purpose of the present invention is to improve the stability, reliability and tolerance of a 650nm vertical cavity surface emitting laser element by adjusting and improving the operating parameters of a wet oxygen furnace so that the wet oxygen aperture shape of the epitaxial layer of the 650nm vertical cavity surface emitting laser element is formed to be substantially circular.

[0006] To achieve the above-mentioned purpose, the present invention discloses a method for forming a wet oxygen aperture shape of a vertical cavity surface emitting laser element. The method comprises the steps of: placing a vertical cavity surface emitting laser wafer into a wet oxygen furnace, wherein the vertical cavity surface emitting laser wafer has a circular vertical cavity surface emitting laser mesa with a diameter of 25um to 30um; evacuating the wet oxygen furnace; heating the wet oxygen furnace to 250 to 350°C and maintaining it for a first time period, and introducing N2 gas and H2O gas into the wet oxygen furnace during the first time period; continuously introducing the N2 gas and the H2O gas into the wet oxygen furnace, while heating the wet oxygen furnace to 350°C. ~450℃ and maintain it for a second time period; continue to introduce the N2 gas and the H2O gas into the wet oxygen furnace, and at the same time increase the temperature of the wet oxygen furnace to 400~450℃ and maintain it for a third time period; maintain the wet oxygen furnace at 400~450℃ to start oxidizing the vertical cavity surface emitting laser wafer; after the oxidation of the vertical cavity surface emitting laser wafer is completed, introduce the N2 gas into the wet oxygen furnace to cool it down to 150℃; and after cooling to 150℃, take out the vertical cavity surface emitting laser wafer from the wet oxygen furnace.

[0007] In one embodiment, before placing the VCSEL wafer into the wet oxygen furnace, the method further includes the steps of: in a wet oxygen process machine standby state, introducing the N2 gas and the H2O gas into the wet oxygen furnace to confirm whether a flow rate of the N2 gas and a flow rate of the H2O gas are normal; and after confirming that the flow rate of the N2 gas and the flow rate of the H2O gas are normal, placing the VCSEL wafer into the wet oxygen furnace.

[0008] In one embodiment, the N 2 gas is introduced into the wet oxygen furnace at 10 liters / minute (L / min).

[0009] In one embodiment, the H 2 O gas is introduced into the wet oxygen furnace at 2 g / h.

[0010] In one embodiment, the temperature of the wet oxygen oven is raised to 250-350° C. at a rate of 10-40° C. / min.

[0011] In one embodiment, the first time period is 6 to 8 minutes.

[0012] In one embodiment, the temperature of the wet oxygen furnace is raised to 400-450° C. at a rate of 10-30° C. / min.

[0013] In one embodiment, the second time period is 1 to 2 minutes.

[0014] In one embodiment, the temperature of the wet oxygen oven is raised to 400-450° C. at a rate of 10-25° C. / min.

[0015] In one embodiment, the third time period is 1 to 2 minutes.

[0016] In one embodiment, the method further comprises the step of taking out the VCSEL wafer from the wet oxygen furnace and allowing the VCSEL wafer to cool naturally at room temperature.

[0017] After referring to the accompanying drawings and the embodiments described below, a person skilled in the art will be able to understand other objects, technical means and implementation schemes of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a method for forming a wet oxygen aperture shape for a vertical cavity surface emitting laser component of the present invention; and

[0019] Figure 2 It is a schematic top view of a VCSEL wafer of the present invention, which shows that the VCSEL wafer has a circular VCSEL mesa with a diameter of 25 um to 30 um.

[0020] Description of Reference Numerals

[0021] 100: Methods

[0022] 200: Vertical Cavity Surface Emitting Laser Wafer

[0023] D: diameter

[0024] S101~S115: steps. DETAILED DESCRIPTION

[0025] The present invention will be explained below by way of examples, and the examples of the present invention are not intended to limit the present invention to any specific environment, application or special method as described in the examples. Therefore, the description of the examples is only for the purpose of explaining the present invention, and is not intended to limit the present invention. It should be noted that in the following examples and drawings, elements that are not directly related to the present invention have been omitted and are not shown, and the dimensional relationship between the elements in the drawings is only for easy understanding, and is not intended to limit the actual proportion.

[0026] One embodiment of the present invention is Figure 1 , which is a flow chart of a method 100 for forming a wet oxygen aperture shape of a vertical cavity surface emitting laser component.

[0027] First, in step S101, a VCSEL wafer is placed in a wet oxygen furnace, wherein the VCSEL wafer has a circular VCSEL mesa with a diameter of 25um to 30um. In this embodiment, the VCSEL wafer may be a 4-inch wafer. For example, Figure 2 The schematic top view of the VCSEL wafer 200 of the present invention is shown, which shows that the VCSEL wafer 200 has a circular VCSEL mesa with a diameter D of 25um to 30um. A person skilled in the art can understand that the VCSEL mesa is a structure formed by epitaxial layer growth, masking, exposure, development and etching during the manufacturing process of the 650nm VCSEL element, so it will not be described in detail here.

[0028] Subsequently, in step S103, the wet oxygen furnace is evacuated. In step S105, the wet oxygen furnace is heated to 250-350°C and maintained for a first time period, and N2 gas and H2O gas are introduced into the wet oxygen furnace in the first time period. In step S107, the N2 gas and the H2O gas are continuously introduced into the wet oxygen furnace, and the wet oxygen furnace is heated to 350-450°C and maintained for a second time period. In step S109, the N2 gas and the H2O gas are continuously introduced into the wet oxygen furnace, and the wet oxygen furnace is heated to 400-450°C and maintained for a third time period. The introduction of N2 gas and H2O gas in the first time period described in step S105 refers to the introduction of N2 gas and H2O gas starting from the constant temperature stage. The continuous introduction of N 2 gas and H 2 O gas in steps S107 and S109 refers to maintaining the introduction of N 2 gas and H 2 O gas during the temperature rise and constant temperature stages.

[0029] Next, in step S111, the wet oxygen furnace is maintained at 400-450°C to start oxidation of the VCSEL wafer. In detail, once the temperature of the wet oxygen furnace reaches 400-450°C, it means that the temperature required for oxidation has been reached, and oxidation begins at this time. Thereafter, in step S113, after the oxidation of the VCSEL wafer is completed, the N2 gas is introduced into the wet oxygen furnace to cool it down to 150°C. In detail, after the oxidation of the VCSEL wafer begins, when the wet oxygen aperture reaches the predetermined target, it means that the oxidation is completed, so N2 gas is subsequently introduced to cool it down. In practice, step S113 takes about 1 hour to cool down to 150°C. In step S115, after cooling to 150°C, the VCSEL wafer is taken out of the wet oxygen furnace.

[0030] In one embodiment, before step S101, method 100 may further include the steps of: in a wet oxygen process machine standby state, introducing the N2 gas and the H2O gas into the wet oxygen furnace to confirm whether a flow rate of the N2 gas and a flow rate of the H2O gas are normal; and after confirming that the flow rate of the N2 gas and the flow rate of the H2O gas are normal, placing the VCSEL wafer into the wet oxygen furnace. In this way, it can be ensured that the wet oxygen process can obtain the expected results. The above-mentioned wet oxygen process machine refers to a machine that includes a wet oxygen furnace for performing a wet oxygen process.

[0031] In one embodiment, the N 2 gas is preferably introduced into the wet oxygen furnace at 10 liters / minute (L / min).

[0032] In one embodiment, the H 2 O gas is preferably introduced into the wet oxygen furnace at 2 g / h.

[0033] In one embodiment, the wet oxygen oven is heated to 250-350° C., preferably at a rate of 10-40° C. / min.

[0034] In one embodiment, the first time period is preferably 6 to 8 minutes.

[0035] In one embodiment, the wet oxygen oven is heated to 400-450° C., preferably at a rate of 10-30° C. / min.

[0036] In one embodiment, the second time period is preferably 1 to 2 minutes.

[0037] In one embodiment, the wet oxygen oven is heated to 400-450° C., preferably at a rate of 10-25° C. / min.

[0038] In one embodiment, the third time period is preferably 1 to 2 minutes.

[0039] It should be noted that the above parameters such as the time period and the heating rate are exemplified as preferred parameters to achieve the purpose of forming the wet oxygen aperture shape of the epitaxial layer of the 650nm vertical cavity surface emitting laser element into a substantially circular shape. However, any adjustment of these parameters made by a person of ordinary skill in the art based on the steps of the method of the present invention shall fall within the scope of protection of the present invention.

[0040] In one embodiment, after step S115, method 100 may further include the step of taking out the VCSEL wafer from the wet oxygen furnace and allowing the VCSEL wafer to cool naturally at room temperature. In other embodiments, after taking out the VCSEL wafer from the wet oxygen furnace, the VCSEL wafer may be placed in a very low temperature environment for cooling to accelerate the cooling speed.

[0041] In summary, the present invention provides a method for improving the wet oxygen aperture shape of a vertical cavity surface emitting laser device, which adjusts and improves the operating parameters of a wet oxygen furnace to form the wet oxygen aperture shape of the epitaxial layer of a 650nm vertical cavity surface emitting laser device into a substantially circular shape. Therefore, the present invention can effectively improve the stability of the 650nm vertical cavity surface emitting laser device and enhance the reliability and tolerance.

[0042] The above embodiments are only used to illustrate the embodiments of the present invention and to explain the technical features of the present invention, and are not used to limit the protection scope of the present invention. Any changes or equivalent arrangements that can be easily completed by a person skilled in the art belong to the scope claimed by the present invention, and the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for forming a wet oxygen aperture shape of a vertical cavity surface emitting laser element, the method comprising the following steps: Putting a vertical cavity surface emitting laser wafer into a wet oxygen furnace, wherein the vertical cavity surface emitting laser wafer has a circular vertical cavity surface emitting laser table with a diameter of 25um to 30um; The wet oxygen furnace is evacuated; The wet oxygen furnace is heated to 250-350° C. and maintained for a first time period, and N2 gas and H2O gas are introduced into the wet oxygen furnace during the first time period; Continuously introducing the N2 gas and the H2O gas into the wet oxygen furnace, while raising the temperature of the wet oxygen furnace to 350-450° C. and maintaining the temperature for a second time period; Continuously introducing the N2 gas and the H2O gas into the wet oxygen furnace, while raising the temperature of the wet oxygen furnace to 400-450° C. and maintaining it for a third time period; Maintaining the wet oxygen oven at 400-450° C. to begin oxidation of the VCSEL wafer; After the VCSEL wafer is oxidized, N2 gas is introduced into the wet oxygen furnace to cool the temperature to 150° C.; and After the temperature is lowered to 150° C., the VCSEL wafer is taken out from the wet oxygen furnace.

2. The method of claim 1, wherein: Before placing the vertical cavity surface emitting laser wafer into the wet oxygen furnace, the method further comprises the following steps: In a wet oxygen process machine standby state, introducing the N2 gas and the H2O gas into the wet oxygen furnace to confirm whether a flow rate of the N2 gas and a flow rate of the H2O gas are normal; and After confirming that the flow rates of the N 2 gas and the H 2 O gas are normal, the VCSEL wafer is placed in the wet oxygen furnace.

3. The method of claim 1, wherein: The N2 gas was introduced into the wet oxygen furnace at 10 liters / minute.

4. The method of claim 1, wherein: The H2O gas was introduced into the wet oxygen furnace at 2 g / h.

5. The method of claim 1, wherein: The temperature of the wet oxygen furnace is raised to 250-350° C. at a rate of 10-40° C. / min.

6. The method of claim 1, wherein: The first time period is 6 to 8 minutes.

7. The method of claim 1, wherein: The temperature of the wet oxygen furnace is raised to 400-450° C. at a rate of 10-30° C. / min.

8. The method of claim 1, wherein: The second time period is 1 to 2 minutes.

9. The method of claim 1, wherein: The temperature of the wet oxygen furnace is raised to 400-450°C at a rate of 10-25°C / min.

10. The method of claim 1, wherein: The third time segment is 1 to 2 minutes.

11. The method of claim 1, further comprising the steps of: The vertical cavity surface emitting laser wafer is taken out from the wet oxygen furnace and is allowed to cool naturally at room temperature.

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