Project Title:

Large-area SiC-on-insulator (SiCOI) Substrates for High-temperature Electronics

94-1	01.03	6000		

Large-area SiC-on-insulator (SiCOI) Substrates for High-
temperature Electronics
 

Abstract:

This Phase I program will fabricate low-defect, high-quality SiC 
(using carbonized ultrathin silicon-on-insulator (SOI) structures) 
as a lattice-matched buffer layer for CVD growth of SiC device 
structures. Recently, Spire demonstrated for the first time the 
fabrication of ultrathin Si on SiO2 (140 A) by using the low-energy 
Separation by IMplantation of OXygen (SIMOX) process. SiC thin 
films will be fabricated by carbonizing the ultrathin Si top layer 
of SIMOX wafers. The carbonization technique has produced the 
lowest defect density in epitaxial SiC on Si; however, due to the 
different lattice constants, a strained layer exists at the 
interface which limits the usefulness of this material for device 
applications. 
Ultrathin Si films will allow rapid conversion of the entire Si 
layer to SiC, since the SiC only contacts SiO2, which is amorphous 
and softens at the carbonization temperature. In the absence of a 
lattice mismatch, the source of stress is eliminated (as in SIMOX), 
thus paving the way for formation of a high-quality SiC layer. 
Phase I will produce SiC buffer layers under varying material and 
processing conditions, and epitaxial SiC layers, by CVD, on the 
lowest-defect material. Phase II would include optimization of the 
processing parameters and fabrication of device structures for 
material evaluation. 

Fabrication of large-area, inexpensive, Si-based substrates for 
growth of low-defect SiC and GaN films will enable for radiation-
hard, high-temperature electronics. These substrates are essential 
for integration of LEDs, lasers, detectors, and a variety of other 
devices into Si microelectronic chips. 

silicon carbide (SiC), carbonization, gallium nitride (GaN), atomic 
layer epitaxy (ALE), silicon-on-insulator (SOI) 

Spire Corporation
One Patriots Park
Bedford, MA 01730-2396
Phone number: (617) 275-6000