Project Title:

Feedback-Controlled, MetalOrganic-Chemical-Vapor- Deposition Reactor for the Indium-Gallium-

92-1-08.27-6000                                                    NAS07-1210
Feedback-Controlled, MetalOrganic-Chemical-Vapor-
     Deposition Reactor for the Indium-Gallium-
Arsenic-Phosphorus Materials System
Spire Corporation
One Patriots Park
Bedford, MA  01730-2396
Nasser H. Karam                                      (617-275-6000)

Abstract:

     MetalOrganic chemical vapor deposition (MOCVD) is the leading
material technology for fabricating III-V multilayer structures
for semiconductor devices. Whereas these devices require precise
control of composition and thickness to maintain high yield and
performance, current MOCVD growth processes operate in an uncon-
trolled mode and require frequent calibration runs to maintain
reproducibility. These deficiencies result in reduced yield and
throughput and, therefore, increased costs. The goal of Phase I is
to identify and demonstrate the feasibility of compatible sensor
technologies which can provide in-situ monitoring and feedback
control of wafer growth in the InGaAs(P)/InP material system. The
approach will implement two types of sensors. The first measures
the concentration of the reactant sources in the gas phase. This
information is then used to provide real-time control for the
growth-rates and compositions of the deposited thin films. The
second sensor is a wafer that measures thicknesses and
compositions of films as they are deposited. The project will
design a highly uniform, single-wafer, reaction chamber that
incorporates the control sensors. Next, Phase I will establish the
feasibility of the key sensors by conducting a breadboard
demonstration. In Phase II, the reaction chamber will be built and
real-time feedback control will be demonstrated.

Potential Commercial Application:

Potential Commercial Applications:  Development of a feedback-
controlled reactor will significantly advance the state-of-the-art
in MOCVD materials growth. Feedback-controlled reactors will be
attractive to manufacturers of multi-layer III-V devices such as
diode lasers and solar cells. Additionally, the ability to produce
complex structures at significantly improved yields will result in
the lower cost of commercial wafers.

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