Accession Number : ADA181339

Title :   An In-Situ Study of Aqueous HF Treatment of Silicon by Contact Angle Measurement and Ellipsometry.

Descriptive Note : Technical rept.,

Corporate Author : NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY

PDF Url : ADA181339

Report Date : 05 Jun 1987

Pagination or Media Count : 35

Abstract : The operation of the MOSFET, one of the most common microelectronic devices, is dependent on application of an electric field across a thin insulating film (gate) of silicon dioxide to a Si substrate beneath. High quality performance of these devices requires cleaning and passivation of the silicon surface. The use of hydrofluoric acid as a wet chemical etch for removal of SiO2 from Si is common in the fabrication of MOSFET devices. Hydrofluoric acid is known the rapidly etch silicon dioxide but to only mildly attack Si(1), which makes it a useful agent for removal of native SiO2 from Si, before thermal oxidation to form the gate insulator, for delineation purposes and for opening contact holes through the SiO2 to the Si substrate. Since the operation of MOSFET devices is dependent on the quality of the Si-SiO2 interface, it is important to understand the effect of HF treatments on both SiO2 and Si. In this paper we describe the results of experiments using ellipsometry and contact angle measurement applied in-situ, that is, in the solution ambient containing Hydrogen fluoride, to study the changes which HF solutions impart to Si and SiO2 surfaces.

Descriptors :   *ETCHING, *HYDROGEN FLUORIDE, *MOSFET SEMICONDUCTORS, *SILICON, *SURFACE ANALYSIS, ELLIPSOMETERS, FABRICATION, GATES(CIRCUITS), HOLES(OPENINGS), HYDROFLUORIC ACID, CHEMICALS, ANGLES, ELECTRICAL INSULATION, MEASUREMENT, MICROELECTRONICS, OPENING(PROCESS), OPERATION, OXIDATION, PASSIVITY, SILICON DIOXIDE, SUBMINIATURE ELECTRONIC EQUIPMENT, SUBSTRATES, SURFACES, THERMOCHEMISTRY, THIN FILMS, CHEMICAL REACTIONS, SURFACE PROPERTIES, LASER BEAMS

Subject Categories : Crystallography
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE