Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Technique for elimination of polysilicon stringers in direct moat field oxide structure










Image Number 3 for United States Patent #4908683.

The problem of unwanted residual polysilicon stringers along the sidewalls of a field oxide layer employed in direct moat wafer processing is avoided by a processing scheme in which the sidewalls of the aperture in the field oxide layer are initially tapered prior to formation of the polysilicon layer to be used for the gate electrode(s). Because of the graduated thickness of the sidewalls of the field oxide layer, the thickness of the polysilicon layer formed thereon is substantially uniform over the entirety of the substrate. As a result, during subsequent masking of the polysilicon layer to define the gate electrode(s), all unmasked portions of the polysilicon are completely etched, leaving no residual material (e.g. stringers) that could be a source of device contamination. After the polysilicon gate has been delineated, the sloped sidewalls of the field oxide are removed (by anisotropic etching), so that the sidewalls of the apertures or windows of the field oxide layer will be perpendicular to the planar surface of the substrate, thus facilitating proper formation of dielectric (oxide) spacers therealong, which thereby provide separation between contact materials and the junction created by shallow ion implantation of dopants through the field oxide aperture.








 
 
  Recently Added Patents
Vanadium, cobalt and strontium additives for use in aluminum back solar cell contacts
Data scrambling in memory devices
High-density 3-dimensional structure
Method and apparatus for disease diagnosis and screening using extremely low frequency electromagnetic fields
Rupture resistant system
Commissioning incoming packet switched connections
Implantable medical devices including elongated conductor bodies that facilitate device and lead configuration variants
  Randomly Featured Patents
Temperature-compensated weighing apparatus
Computer keyboard having top molded housing with rigid pointing stick integral and normal to front surface of housing as one unit part to be used with strain sensors in navigational control
Compounds and methods for kinase modulation, and indications therefor
Distributor for the deposit of melted products in the interior of containers having the same or different shape and size
Feeding herbicide to a roller for transfer onto plants
Silver halide color photographic lightsensitive material
Vapor exchange medium
Method for increasing the batch size of a barrel epitaxial reactor and reactor produced thereby
Valve with latching means
Engine hood for a tractor