Observations on selectivity loss during tungsten CVD. [Growth on SiO/sub 2/]

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6816337

Creighton, J R

Possible mechanisms for the loss of selectivity during tungsten CVD (i.e., growth on SiO/sub 2/) were investigated using a dual vacuum system composed of a growth chamber and a UHV analysis chamber equipped with Auger and mass spectroscopy. An oxide-covered silicon sample could be transferred between the two chambers while under vacuum to maintain surface composition integrity. With this experimental system, we have found evidence for a selectivity loss mechanism which involves desorption of tungsten subfluorides from tungsten surfaces. The disproportionation of the subflorides then produces a reactive state of tungsten on the SiO/sub 2/ surfaces that leads directly to selectivity loss.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6816337
• Report Number(s): SAND-86-2867C; CONF-8611130-1; ON: DE87003514
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMICAL VAPOR DEPOSITION
DEPOSITION
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
METALS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
REDUCTION
REFRACTORY METAL COMPOUNDS
SEMIMETALS
SILICA
SILICON
SILICON COMPOUNDS
SILICON OXIDES
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN COMPOUNDS
TUNGSTEN FLUORIDES
VACUUM SYSTEMS