Method for producing a light emitting device

• US 20070065960A1
• Filed: 11/11/2004
• Published: 03/22/2007
• Est. Priority Date: 11/12/2003
• Status: Active Grant

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Fukshima, Hiroshi, Tanaka, Kenichiro, Kubo, Masao, Inoue, Akira, Masui, Mikio, Matsui, Shinji
• Granted Patent: US 7,709,282 B2
• Time in Patent Office: Days
• US Class Current: 438/42
• 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 a n-type semiconductor layer and a p-type semiconductor layer is layered on a transparent crystal substrate, comprising the steps of:

forming a transfer layer on at least a part of the transparent crystal substrate or the light-emitting layer, which transfer layer is softened or set 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; and

forming a minute unevenness structure for preventing multiple reflection based on the minute unevenness structure transferred to the transfer layer.

2. A production method according to claim 1, wherein the step of forming the minute unevenness structure in the light-emitting layer includes a step of 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 step of forming the transfer layer includes a step of applying a silicon organic solvent to at least the part of the transparent crystal substrate or the light-emitting layer to form the transfer layer, and the step of forming the minute unevenness structure for preventing the multiple reflection includes a step of dry etching the transfer layer with a chlorine gas using the transfer layer as a resist mask to form the minute unevenness structure for preventing the multiple reflection in the transparent crystal substrate or the light-emitting layer.

4. A production method according to claim 3, wherein the step of forming the minute unevenness structure for preventing the multiple reflection in the light-emitting layer includes a step of pressing a mold having an upper flat portion to be located near the bottoms of the minute unevenness structure for preventing the multiple reflection and a lower flat portion to be located at a position lowered from the upper flat portion by about the thickness of the upper semiconductor layer of the light-emitting layer against the transfer layer to transfer an upper flat portion and a lower flat portion 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 using the transfer layer as a resist mask.

5. A production method according to claim 4, wherein the etching step includes a step of adjusting a selection ratio of the etching speed of the light-emitting layer to that of the resist from twofold to fourfold.

6. A production method according to claim 5, wherein the step of applying the silicon organic solvent to form the transfer layer includes a step of applying the silicon organic solvent by potting or spray coating.

7. A production method according to claim 6, wherein a pressing pressure of the mold is 5 MPa or higher and 150 MPa or lower.

8. A production method according to claim 7, wherein a step of forming an unevenness structure larger than the minute unevenness structure on the minute unevenness structure of the light-emitting layer is carried out after the step of forming the minute unevenness structure for preventing the multiple reflection in the light-emitting layer.

9. A production method according to claim 8, wherein the unevenness structure has the shape of a prism or a microlens.

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

11. A production method according to claim 3, wherein a pressing pressure of the mold is 5 MPa or higher and 150 MPa or lower.

12. A production method according to claim 3, wherein a step of forming an unevenness structure larger than the minute unevenness structure on the minute unevenness structure of the light-emitting layer is carried out after the step of forming the minute unevenness structure for preventing the multiple reflection in the light-emitting layer.

13. A production method according to claim 1, wherein the step of forming the transfer layer includes a step of applying a silicon organic solvent to at least the part of the transparent crystal substrate or the light-emitting layer to form the transfer layer, and the step of forming the minute unevenness structure for preventing the multiple reflection includes a step of dry etching the transfer layer with a chlorine gas using the transfer layer as a resist mask to form the minute unevenness structure for preventing the multiple reflection in the transparent crystal substrate or the light-emitting layer.

14. A production method according to claim 1, wherein the step of applying the silicon organic solvent to form the transfer layer includes a step of applying the silicon organic solvent by potting or spray coating.