Method of fabricating GaN device with laser

• US 20080113463A1
• Filed: 12/26/2006
• Published: 05/15/2008
• Est. Priority Date: 11/09/2006
• Status: Abandoned Application

• Current Assignee: National Central University
• Original Assignee: National Central University
• Inventors: Lin, Ching-Liang, Chan, Po-Han, Liu, Cheng-yi
• Application Number:
  US11/645,165
• Publication Number:
  US 20080113463A1
• Time in Patent Office: Days
• US Class Current: 438/46
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A laser is used in fabricating a thin film gallium nitride (GaN) light emitting diode (LED). The laser has a wave length to be absorbed by GaN. The laser is used to define a GaN grain. And the laser is used to lift off a substrate after obtaining a bonding layer of GaN. Fabrication procedure is thus simplified.

Claims

1. A method of fabricating a gallium nitride (GaN) device with laser, comprising steps of:

(a) obtaining a substrate and growing a buffer layer, an n-type GaN and a p-side up GaN to obtain an epitaxy structure;

(b) bonding said epitaxy structure to bond with another substrate by using a bonding layer and defining a grain with laser;

(c) lifting off said substrate stripped out by laser illumination and etching said buffer layer to roughen a surface of said buffer layer; and

(d) deposing a dielectric layer on said grains and said buffer layer and etching out an n-type electrode to obtain a grain of thin film light emitting diode (LED) structure.

2. The method according to claim 1,

wherein said substrate is made of a material selected from a group consisting of sapphire, silicon carbide (SiC), gallium arsenide (GaAs), lithium dioxogallate (LiGaO₂) and aluminum nitride (AlN).

3. The method according to claim 1,

wherein said epitaxy structure is an epitaxy layer of III-V group elements;

and

wherein said epitaxy structure is made of a material selected from a group consisting of GaAs, indium phosphide (InP), GaN, gallium indium nitride (GaInN), aluminum gallium indium nitride (AlGaInN), indium nitride (InN), gallium indium arsenic nitride (GaInAsN) and gallium indium phosphorous nitride (GaInPN).

4. The method according to claim 1,

wherein said epitaxy structure is obtained through a method selected from a group consisting of metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) and hydride vapor phase epitaxy (HVPE).

5. The method according to claim 1,

wherein said bonding with said another substrate is selected from a group consisting of a metal bonding, an organic polymer adhesion and an electroplating.

6. The method according to claim 5,

wherein said bonding is selected from a group consisting of Au (gold)-Au metal bonding, silver epoxy adhesion, conductive polymer adhesion and electroplating.

7. The method according to claim 1,

wherein said another substrate is made of a material selected from a group consisting of copper (Cu), nickel (Ni), silicon (Si), aluminum nitride (AlN) and beryllium oxide (BeO).

8. The method according to claim 1,

wherein said bonding layer is made of a material selected from a group consisting of an ohmic contact metal, a reflective metal and an under-bump metallization layer with bonding capacity;

and

wherein said bonding layer is electrically connected with GaN.

9. The method according to claim 8,

wherein said bonding layer is a bonding selected from a group consisting of Au-Si, Au-Ge(germanium), Au-Sn(tin), Pd-In (indium) and Pb-Sn

10. The method according to claim 1,

wherein said laser used in lifting off said substrate is selected from a group consisting of a solid state laser and an excimer laser.

11. The method according to claim 10,

wherein said laser used in lifting off said substrate is selected from a group consisting of Nd:

YAG laser and KrF excimer laser.

12. The method according to claim 1,

wherein said etching on said buffer layer is selected from a group consisting of a physical etching and a chemical etching.

13. The method according to claim 12,

wherein said etching on said buffer layer is selected from a group consisting of inductively coupled plasma (ICP) dry etching and photoelectrochemical wet-etching.

14. The method according to claim 1,

wherein said dielectric layer is a protecting layer to said grain and is coordinated in light extraction.

15. A method of fabricating a GaN device with laser, comprising steps of:

(a) obtaining a substrate and growing a buffer layer, an n-type GaN and a p-side up gallium nitride (GaN) to obtain an epitaxy structure and defining a grain with laser;

(b) bonding said epitaxy structure to bond with another substrate by using a bonding layer;

(c) lifting off said substrate striiped out by stripped out by laser illumination and etching said buffer layer to roughen a surface of said buffer layer; and

(d) deposing a dielectric layer on said grains and said buffer layer and etching out a n n-type electrode to obtain a grain of thin film LED structure.