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
Respirator belt having bumper cushion
Recombinant vectors for use in position-independent transgene expression within chromatin
Continuous geospatial tracking system and method
(4926
Apparatus for controllable delay cell and associated methods
Composite filtration membranes and methods of preparation thereof
State control of remote hosts for management of distributed applications
  Randomly Featured Patents
Refuse collection device
Continuous process to wrap entangled yarn
Gesture coach
Light-sensitive diazoketone and azide compositions and photographic elements
Back pain/back health protocol
Silicon nitride sintered body
Vehicle loading and unloading system
Method for producing ferrite magnet
Methods and apparatus for graphical display and editing of flight plans
Dynamic program suspension