Form 9.B Project Summary






Project Title:

A Validated Computational Model to

Enable Real Time Control of the Pulsed

OMCVD Process for Heteroepitaxy of

Compound Semiconductors

Technical Abstract (Limit 200 words)

Pulsed Organo-Metallic Chemical Vapor

Deposition (OMCVD) is being investigated for

ground-based and microgravity applications by

NASA and North Carolina State University (NCSU)

as an effective technique to eliminate defects

during heteroepitaxial growth of compound

semiconductors. This technique requires tight

process control to regulate the sequence and

duration of pulses in response to instantaneous

growth patterns. It is proposed to develop and

validate an advanced computational tool as a

critical enabling technology for process control for

pulsed OMCVD.

Phase I will focus on developing a kinetic model for

the surface reaction pathways during OMCVD. The

model will be tested by implementation into an

existing CFD code. A multi-dimensional

computational model will be developed for the

NCSU OMCVD reactor and detailed simulations of

flow, heat/mass transfer and gas/surface chemistry

will be performed. The model predictions for

ground-based growth will be validated against

measured NCSU data . The model will also be used

in support of the NCSU space flight experiment

design and operation. The Phase II work will focus

on extensive validation of the chemistry models

over a range of operating conditions. Advanced

Monte Carlo models will be applied to understand

the microstructural evolution of the film. A series of

parametric simulations will be performed to

determine optimal operating conditions for the

reactor. The model will be fully validated using

ground-based and microgravity flight data.

Potential Commercial Applications (Limit 200 words)

Heteroepitaxy of compound semiconductor

materials on heterogeneous substrates is a vital

technology for optoelectronics in the blue to

ultra-violet wavelength region and non-linear optics

in the infra-red region and power devices and

integrated sensor devices. The proposed model will

be an enabling technology in demonstrating

defect-free heteroepitaxial growth by facilitating

appropriate control of the pulsed OMCVD process.

Name and Address of Principal Investigator (Name,

Organization Name, Mail Address, City/State/Zip)

Dr. Samuel A. Lowry

CFD Research Corporation

215 Wynn Drive

Huntsville , AL 35805

Name and Address of Offeror (Firm Name, Mail Address,


Dr. Andrzej J. Przekwas

CFD Research Corporation

215 Wynn Dr.

Huntsville , AL 35805