Background

There is considerable interest in the growth and characterization of Gallium Nitride (GaN) thin films for applicaton in optoelectronic and high-temperature devices, due to chemical stability at high temperatures, excellent mechanical properties, good thermal conductivity and a high breakdown field. Particularly, the wide bandgaps of AlN and GaN makes this material promising for ultra-violet (UV) diode emitters.

Conventional methods require these devices be made through heteroepitaxial growth on expensive and size-limited substrate materials such as silicon carbide or sapphire. These methods depend on a nitrogen source for the formation of GaN which, when using a silicon substrate instead, results in the formation of an interlayer of silicon nitride which is not a useful surface upon which to grow epitaxial GaN.

Thus, there is substantial need for a method of growing Gallium Nitride on a silicon substrate.

Technology Overview

NC State researchers have developed a novel method to effectively grow and integrate epitaxial films of GaN on a silicon substrate. This invention provides the mechanisms for the dynamic control of the deposition processes on a monolayer-by-monolayer basis to effect optimal atomic reconstruction of the silicon and nitrogen at the silicon substrate surface.

Silicon provides less expensive and larger area substrates for the fabrication of III-nitrides-based light-emitting diodes and lasers. Using domain matching epitaxy, these films are ordered on the silicon in such a way as to allow for cost-effective co-integration of wide band-gap optoelectronic devices with large-scale silicon based microelectronics. It is also possible to modify the structure formation of the epilayer during growth, without interrupting the process, to incorporate other material structures or dopants.

Benefits

Allows growth of GaN on silicon substrates
Reduces GaN growth costs

Applications

LED manufacturing
Semiconductor manufacturing
Microelectronic devices

Growth and Integration of Epitaxial Gallium Nitride Films with Silicon-Based Devices

Patents

IP Status