Method for producing a light emitting device

• US 7,709,282 B2
• Filed: 11/11/2004
• Issued: 05/04/2010
• Est. Priority Date: 11/12/2003
• Status: Expired due to Fees

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Inoue, Akira, Masui, Mikio, Matsui, Shinji, Fukshima, Hiroshi, Tanaka, Kenichiro, Kubo, Masao
• Primary Examiner(s): Bryant; Kiesha R
• Assistant Examiner(s): Yang; Minchul
• Application Number:
  US10/575,489
• Publication Number:
  US 20070065960A1
• Time in Patent Office: 2,000 Days
• Field of Search: 216/24, 216/41, 257/25, 257/81, 257/91, 257/95, 257 98-100, 257/103, 257/E21.499, 257/E21.502, 257/E21.503, 438/22, 438/46, 438/47, 438/918, 438/9, 438/42, 438/26
• US Class Current: 438/26
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A production method for producing a light-emitting device 1 in which a light-emitting layer at least comprised of a n-type substrate bearing layer 3 and a p-type substrate bearing layer 4 is layered on a transparent crystal substrate 2 is provided with a step of forming a transfer layer 5 on at least a part of the transparent crystal substrate 2 or the light-emitting layer 3, 4, which transfer layer 5 is softened or set upon supplying an energy thereto; a step of pressing a mold 6 formed with a minute unevenness structure 61 against the transfer layer 5 to transfer the minute unevenness structure 61 to an outer surface of the transfer layer 5, and a step of forming a minute unevenness structure 21, 34 for preventing multiple reflection based on the minute unevenness structure 51 transferred to the transfer layer 5.

Claims

1. A production method for producing a light-emitting device in which a light-emitting layer at least including an n-type semiconductor layer and a p-type semiconductor layer is layered on a transparent crystal substrate, comprising:

applying a silicon organic solution to at least a part of the transparent crystal substrate or the light-emitting layer to form a transfer layer on at least a part of the transparent crystal substrate or the light-emitting layer wherein said transfer layer is 1 to 2 μ

m;

softening or setting said transfer layer upon supplying an energy thereto;

pressing a mold formed with a minute unevenness structure against the transfer layer to transfer the minute unevenness structure to an outer surface of the transfer layer under a pressure of 5 MPa or higher and 150 MPa or lower wherein a pitch is 1 to 3 μ

m,

wherein the mold has an upper flat portion located near a bottom of the minute unevenness structure to be transferred and a lower flat portion located at a position about a thickness of an upper semiconductor layer of the light-emitting layer, the upper flat portion and the lower flat portion are transferred together with the minute unevenness structure to the transfer layer; and

forming electrode-forming portions by etching the upper and lower semiconductor layers of the light-emitting layer when dry etching is carried out using the transfer layer as a resist mask; and

dry etching the transfer layer with a chlorine gas using the transfer layer as a resist mask to form a minute unevenness structure for preventing multiple reflection in the transparent crystal substrate or the light-emitting layer.

2. A production method according to claim 1, wherein forming the minute unevenness structure in the light-emitting layer includes separating the transparent crystal substrate from the light-emitting layer after a substrate bearing layer is formed on a surface of the light-emitting layer where electrodes are to be formed.

3. A production method according to claim 2, wherein the etching comprises adjusting a selection ratio of the etching speed of the light-emitting layer to that of the resist from twofold to fourfold.

4. A production method according to claim 3, wherein applying the silicon organic solvent to form the transfer layer comprises applying the silicon organic solvent by potting or spray coating.

5. A production method according to claim 4, comprising forming an unevenness structure larger than the minute unevenness structure on the minute unevenness structure of the light-emitting layer after forming the minute unevenness structure for preventing the multiple reflection in the light-emitting layer.

6. A production method according to claim 5, wherein the unevenness structure has the shape of a prism or microlens.

7. A production method according to claim 1, wherein the etching comprises adjusting a selection ratio of the etching speed of the light-emitting layer to that of the resist from twofold to fourfold.

8. A production method according to claim 1, comprising forming an unevenness structure larger than the minute unevenness structure on the minute unevenness structure of the light-emitting layer after forming the minute unevenness structure for preventing the multiple reflection in the light-emitting layer.

9. A production method according to claim 1, wherein applying the silicon organic solvent to form the transfer layer comprises applying the silicon organic solvent by potting or spray coating.

10. A production method according to claim 1, wherein the silicon organic solvent comprises:

an alcohol, an ester, a ketone or a mixture of two or more of an alcohol, an ester, and a ketone, and

a silicon alkoxide component, R_nSi(OH)_4-n, where R is H or alky group, and n is an integer of 0 to 3.

11. A production method according to claim 10, wherein the silicon organic solvent contains TEOS or TMOS.

12. A production method according to claim 1, wherein the method further comprises post-baking the transfer layer at or below 120°

C. after the minute unevenness structure is transferred to the transfer layer.