Method for fabricating white light emitting diode using InGaN phase separation

• US 6,303,404 B1
• Filed: 05/28/1999
• Issued: 10/16/2001
• Est. Priority Date: 05/28/1999
• Status: Expired due to Term

• Current Assignee: HC SemiTek Corporation
• Original Assignee: Kwangju Institute Of Science And Technology
• Inventors: Kim, Dong Joon, Song, Keun Man, Moon, Yong Tae, Park, Seong Ju
• Primary Examiner(s): Pham, Long
• Application Number:
  US09/322,393
• Time in Patent Office: 872 Days
• Field of Search: 438/46, 438/47, 438/22, 438/796
• US Class Current: 438/46
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Disclosed is a method for fabricating a white LED which comprises, as a single active layer, an InGaN thin film which enables emission of white light. The InGaN thin film is constructed by taking advantage of the spinodal decomposition of the ternary compound and rapid thermal annealing. When growing the InGaN thin film on an n-type GaN formed on a sappier substrate under a growth condition, the thin film undergoes spinodal decomposition into two phases which show photoluminescence of a wavelength range from violet to blue and from green to blue, respectively, after which the surface of the thin film is thermally stabilized by rapid thermal annealing and the photoluminescence of the In-deficient phase is improved, so as to give intensive white photoluminescence to the InGaN single active layer. The LED which recruits such a single active InGaN thin film is superb in light emission efficiency and can be fabricated in a significantly reduced process steps.

Claims

1. A method for fabricating a nitride semiconductor-based white light emitting diode using InGaN phase separation, in which an InGaN thin film is subjected to phase separation while growing under a growth condition and then, to rapid thermal annealing to become an active layer which emits white light in the white white light emitting diode without phosphor materials, wherein the phase separated InGaN thin film which emits white light is grown to a thickness of 2 nm-300 nm at a temperature of 450-850°

C. by a chemical vapor deposition process or a molecular beam epitaxy process using silane (SiH₄) at an amount of 3-100 sccm as an n-type dopant source.

3. A method as set forth in claim 1, wherein the phase-separated InGaN thin film which emits white light has a multi-quantum well structure comprising phase-separated InGaN/In_xAl_yGa₁₋

x−

yN (0≦

x,y≦

1) multi-quantum wells.

2. A method of fabricating a nitride semiconductor-based white light emitting diode having a single active layer, i.e., an InGaN thin film which emits white light, the method comprising:

(a) growing an n-type GaN thin film on a substrate;

(b) growing a phase-separated InGaN thin film which is grown to a thickness of 7.1-200 nm at a temperature of 450-850°

C. by a metalorganic chemical vapor deposition process or a molecular beam epitaxy process using silane (SiH₄) at an amount of 3-100 sccm as an n-type dopant source, the phase-separated InGaN thin film emitting white light;

(c) annealing the InGaN thin film thermally at a temperature of 700-1050°

C. for 0.1-10 min in a nitrogen (N₂) or ammonia (NH₃) atmosphere; and

(d) growing a p-type GaN layer on the InGaN thin film.