Method for controlling the structure and surface qualities of a thin film and product produced thereby
US7501299B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2006 |
| Grant date | Mar 10, 2009 |
| Priority date | — |
| Expiry date | Apr 28, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/34333
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system and method for providing improved surface quality following removal of a substrate and template layers from a semiconductor structure provides an improved surface quality for a layer (such as a quantum well heterostructure active region) prior to bonding a heat sink/conductive substrate to the structure. Following the physical removal of a sapphire substrate, a sacrificial coating such as a spin-coat polymer photoresist is applied to an exposed GaN surface. This sacrificial coating provides a planar surface, generally parallel to the planes of the interfaces of the underlying layers. The sacrificial coating and etching conditions are selected such that the etch rate of the sacrificial coating approximately matches the etch rate of GaN and the underlying layers, so that the physical surface profile during etching approximates the physical surface profile of the sacrificial coating prior to etching. Following etching, a substrate is bonded to the exposed surface which acts as a heat sink and may be conductive providing for backside electrical contact to the active region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.