Method of manufacturing semiconductor light emitting device and oxidation furnace

• US 20030139060A1
• Filed: 12/13/2002
• Published: 07/24/2003
• Est. Priority Date: 12/13/2001
• Status: Active Grant

• Current Assignee: Hironobu Sai
• Original Assignee: Hironobu Sai
• Inventors: Sai, Hironobu
• Granted Patent: US 6,979,581 B2
• Time in Patent Office: Days
• US Class Current: 438/767
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02233 of the semiconductor substrate or a semiconductor layer
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/31666 of AIII BV compounds
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01S 5/0042 On wafer testing, e.g. lasers are tested before separating wafer into chips
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity

Abstract

A sample stand is set in a chamber provided with an observation window on its upper surface and a heater for heating a sample is provided in the vicinity of the sample stand. Then, a microscope, a camera and a television monitor are connected and mounted outside the observation window of the chamber. The microscope is mounted such that a specific layer of the sample is focused on and can be observed. According to a manufacturing method of the preset invention, oxidation treatment is performed in such equipment while an oxidation process of the specific layer (semiconductor layer for selective oxidation) of the sample is observed. As a result, the amount of oxidation of the semiconductor layer for selective oxidation can be strictly controlled, a semiconductor light emitting device which restricts a current into a certain region can be obtained with high yield ratio, and there is obtained an oxidation furnace which can precisely control the amount of oxidation of the semiconductor layer for selective oxidation.

Claims

1. A method of manufacturing a semiconductor light emitting device comprising steps of;

(a) forming a semiconductor laminated part comprising a light emitting layer forming portion and a semiconductor layer for selective oxidation for forming a current injection region on a substrate,

(b) etching away a part of said semiconductor laminated part such that said current injection region and its peripheral region would be left in mesa-shape,

(c) forming a predetermined range of current injection region by oxidizing said semiconductor layer for selective oxidation etched in mesa-shape from its periphery toward its center, while observing said semiconductor layer for selective oxidation from a surface side of said semiconductor laminated part, and

(d) forming electrodes for electrical connection on both sides of said semiconductor laminated part.

2. A manufacturing method according to claim 1, wherein said semiconductor layer for selective oxidation is made of AlAs.

3. A manufacturing method according to claim 1, wherein said light emitting layer forming portion has a double heterostructure in which an active layer is sandwiched by lower and upper spacer layers so as to form a surface emitting laser, a bandgap of said spacer layers being wider than that of said active layer, and wherein said semiconductor laminated part further comprises multilayer reflection films formed on upper and lower sides of said light emitting layer forming portion.

4. A manufacturing method according to claim 3, wherein said active layer is a quantum well structure.

5. A manufacturing method according to claim 1, wherein the step of oxidizing said semiconductor layer for selective oxidation further comprises steps of:

setting said substrate on which said semiconductor laminated part is grown in a chamber, and

oxidizing said semiconductor layer for selective oxidation by supplying vapor which is stable at about 400°

C. to 500°

C. around said semiconductor layer for selective oxidation.

6. A manufacturing method according to claim 5, wherein a vapor supply pipe having a heater is provided on said chamber and said vapor is supplied around said semiconductor layer for selective oxidation by introducing a vapor into said chamber through said vapor supply pipe.

7. A manufacturing method according to claim 5, wherein said vapor is supplied around said semiconductor layer for selective oxidation by generating a vapor in said chamber.

8. A manufacturing method according to claim 5, wherein said substrate is set such that a distance between a surface of said semiconductor laminated part and an inner surface of an upper wall of said chamber would be 10 mm or less and said semiconductor layer for selective oxidation is observed by a microscope from the outside of said chamber.

9. A manufacturing method according to claim 8, wherein a light is irradiated from said microscope to said semiconductor laminated part and a filter is provided in the irradiation pathway of said light, said filter removing light having wavelength shorter than that of visible light.

10. A manufacturing method according to claim 9, wherein a light transmission window is provided on said chamber in the course of the irradiation pathway of the light from said microscope and a thin transparent plate which is 0.1 mm to 0.2 mm in thickness is attached to said light transmission window.

11. A manufacturing method according to claim 10, wherein said light transmission plate is attached on both inner wall and upper wall surfaces of said chamber.

12. An oxidation furnace comprising:

a chamber provided with an observation window on its upper surface;

a sample stand provided in said chamber;

a heater provided in the vicinity of said sample stand to heat a sample provided on said sample stand;

a vapor source supplying a vapor for oxidation to the vicinity of said sample;

a microscope mounted outside said chamber for observing said sample through said observation window,

wherein said sample stand is provided such that a specific layer of said sample can be focused on and observed by said microscope by adjusting a distance between said sample surface and said observation window and oxidation treatment is performed while oxidation process of the specific layer of said sample is observed.

13. An oxidation furnace according to claim 12, wherein said observation window is formed such that a through hole provided in said chamber is closed by a thin transparent plate.

14. An oxidation furnace according to claim 12, wherein there is provided a means for uniformizing the temperature and/or concentration of vapor in the vicinity of said sample.

15. An oxidation furnace according to claim 14, wherein said means comprises a means for heating up a vapor so as to be at the same temperature as the oxidation temperature of said sample or more and a means for introducing it into said chamber.

16. An oxidation furnace according to claim 12, wherein a concave part is formed at a part of said sample stand, said sample being put on said concave part.

17. An oxidation furnace according to claim 12, wherein a convex part is formed around a part of said sample stand on which said sample is put.