Method for fabricating a flip-chip semiconductor optoelectronic device
A method for fabricating flip-chip semiconductor optoelectronic devices initially flip-chip bonds a semiconductor optoelectronic chip attached to an epitaxial substrate to a packaging substrate. The epitaxial substrate is then separated using lift-off technology.
1. A method for fabricating a flip-chip semiconductor optoelectronic device, comprising the steps of:
providing an epitaxial substrate;
forming a sacrificial layer on said epitaxial substrate, which comprises steps of:
forming a first Group III nitride semiconductor layer on said epitaxial substrate;
forming a patterned mask on said first Group III nitride semiconductor layer;
etching said first Group III nitride semiconductor layer; and
removing said patterned mask;
forming a semiconductor light-emitting structure on said sacrificial layer, said semiconductor light-emitting structure including a first surface and a second surface opposite to the first surface of said semiconductor light-emitting structure, wherein said sacrificial layer is on said second surface of said semiconductor light-emitting structure;
forming an n-type electrode and a p-type electrode on said first surface of said semiconductor light-emitting structure;
flip chip bonding said semiconductor light-emitting structure to a packaging substrate including a first surface, a second surface opposite to said first surface of said packaging substrate, a first bond pad formed on said first surface of said packaging substrate, a second bond pad formed on said first surface of said packaging substrate, a first bump formed on said first bond pad, and a second bump formed on said second bond pad, wherein said n-type electrode is electrically attached to said first bump, and said p-type electrode is electrically attached to said second bump;
disposing a transparent adhesive material between said first surface of said packaging substrate and said first surface of said semiconductor light-emitting structure, enclosing said first bond pad, said second bond pad, said first bump, and said second bump; and
separating said epitaxial substrate by etching said sacrificial layer.
2. The method of claim 1 , wherein said epitaxial substrate is a sapphire substrate, a silicon carbide substrate, a lithium aluminate substrate, a lithium gallate substrate, a silicon substrate, a gallium nitride substrate, a zinc oxide substrate, an aluminum zinc oxide substrate, a gallium arsenide substrate, a gallium phosphide substrate, a gallium antimonide substrate, an indium phosphide substrate, an indium arsenide substrate, or a zinc selenide substrate.
3. The method of claim 1 , wherein said sacrificial layer is etched by a wet etch or dry etch, or said sacrificial layer is etched by employing an inductively coupled plasma etcher.
4. The method of claim 1 , wherein the material of said first and second bumps is palladium tin alloy.
5. The method of claim 1 , wherein the material of said n-type electrode is titanium/aluminum/titanium/gold alloy, chromium gold alloy or gold lead alloy.
6. The method of claim 1 , wherein the material of said p-type electrode is nickel gold alloy, platinum gold alloy, chromium gold alloy, tungsten or palladium.
7. The method of claim 1 , further comprising a step of forming a dielectric layer between said n-type electrode and said p-type electrode to increase the hardness of said semiconductor light-emitting structure and to electrically insulate said n-type electrode from said p-type electrode.
8. The method of claim 7 , wherein the material of said dielectric layer is silicon oxide, epoxy resin, silicon nitride, titanium oxide, or aluminum nitride.
9. The method of claim 1 , further comprising a step of forming a protecting layer around said semiconductor light-emitting structure, and said step of forming a protecting layer is performed before said step of separating said epitaxial substrate.
10. The method of claim 9 , wherein the material of said protecting layer is silicon oxide.
11. The method of claim 1 , wherein said step of separating said epitaxial substrate by etching said sacrificial layer is performed employing a wet etch method.
12. The method of claim 1 , wherein the material of said dielectric layer is silicon oxide, epoxy resin or silicon nitride.
13. The method of claim 1 , wherein said packaging substrate is a printed circuit board, a bismaleimide triazine resin printed circuit board, a metal core printed circuit board, a flexible printed circuit board, a ceramic substrate, or a silicon substrate.
14. The method of claim 1 , wherein the material of said semiconductor light-emitting structure is Group III-V compound semiconductor.