Accession Number:

ADA280987

Title:

Atomic Layer Epitaxy of Group IV Materials: Surface Processes, Thin Films, Devices and their Characterization

Descriptive Note:

Semiannual technical rept. 1 Jan-30 Jun 1994

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s):

• Davis, Robert F.

Report Date:

1994-06-01

Pagination or Media Count:

45.0

Abstract:

The viability of Si2Cl6, C2H2 and C2H4 as precursors for chemically self-limiting ALE of SiC has been investigated via XPS and LEED. Si2Cl6 readily adsorbs in a self-limiting manner on a Si100 surface however, neither hydrocarbon will adsorb or react with a Cl-terminated Si surface to 475 deg C. Conversely, partial chlorination of Si100 saturated with C2H2 and C2H4 does occur and implies that Si2Cl6 will adsorbreact with a hydrocarbon terminated surface. Layer-by-layer growth of Beta-SiC on Si100 or 6H-SiC has been achieved with a carrier concentration of approx. 10exp 17cu cm. P-type doping with Al has allowed the achievement of hole concentrations of 4 x 10exp 18 - 2 10exp 20cu cm. Efforts to produce an HBT using Beta-SiC emitters is described. Ni3Si has been employed for the deposition of diamond because of the close lattice match. Under the same growth conditions, diamond particles were obtained on the Ni3Si, but only diamond-like C and graphite on pure Ni substrates. Evidence of oriented particles was observed. REED and TEM of cerium oxide films grown on Si111 substrates has revealed the formation of a dual amorphous layer of CeOx and SiO2 at the Si interface followed by a layer of CeO2. Post annealing in dry oxygen caused the CeOx layer to disappear and the SiO2 layer to thicken. D sub it 6 x 10exp 11sq cm and Q sub f 5 x 10exp 11sq cm. The structure exhibits a high capacitance due to the large dielectric constant of CeO2 and has electrical properties comparable with those of other reported gate insulators on Si.

Descriptors:

• *MATERIALS
• *THIN FILMS
• *EPITAXIAL GROWTH
• *ACETYLENE
• *GROUP IV COMPOUNDS
• *ETHYLENE
• *SILICON CARBIDES
• ANNEALING
• INTERFACES
• PRECURSORS
• HETEROJUNCTIONS
• DIAMONDS
• SUBSTRATES
• ALUMINUM
• OXIDES
• PARTICLES
• DEPOSITION
• OXYGEN
• SURFACES
• ELECTRICAL PROPERTIES
• CARBON
• SEMICONDUCTORS
• DIOXIDES
• CAPACITANCE
• BIPOLAR TRANSISTORS
• CHLORINATION
• EMITTERS
• DOPING
• NICKEL
• VIABILITY
• HYDROCARBONS
• CONSTANTS
• CERIUM
• GRAPHITE
• HOLES(ELECTRON DEFICIENCIES)
• DIELECTRICS
• STRUCTURES
• CRYSTAL LATTICES
• LAYERS
• ADSORPTION

Subject Categories:

• Inorganic Chemistry
• Physical Chemistry
• Laminates and Composite Materials
• Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE