Resources Contact Us Home
Method to solve the dishing issue in CMP planarization by using a nitride hard mask for local inverse etchback and CMP

Image Number 6 for United States Patent #6261923.

A method for forming planarized isolation using a nitride hard mask and two CMP steps is described. A first nitride layer is deposited over a pad oxide layer on the surface of a semiconductor substrate. The first nitride and pad oxide layers are etched through where they are not covered by a mask to provide at least one wide opening and at least one narrow opening where the surface of the substrate is exposed. Trenches are etched into the substrate where it is exposed. An oxide layer is deposited overlying the first nitride layer and within the trenches completely filling the narrow trench wherein a trough is formed over the wide trench. A second nitride layer is deposited over the oxide layer. The second nitride layer is polished away with a polish stop at the oxide layer whereby the second nitride layer is removed except: where it lies within the trough. The oxide layer is etched back where it is not covered by the second nitride layer wherein the oxide layer is planarized except where the oxide layer underlies the second nitride layer. The second nitride layer is removed within the trough whereby oxide horns forming the trough extend vertically upward from the planarized oxide surface. Thereafter, the oxide layer is polished away with a polish stop at the first nitride layer whereby the oxide horns are removed. The first nitride and the pad oxide layers are removed completing formation of the shallow trench isolation.

  Recently Added Patents
Apparatus and method for adapted deblocking filtering strength
System and method for converting biomass to ethanol via syngas
Hydrogenolysis of ethyl acetate in alcohol separation processes
Systems and methods for synchronizing and controlling multiple image sensors
Light emitting device and electronic device
Integrated testing circuitry for high-frequency receiver integrated circuits
Flame-proofed thermoplastic compositions
  Randomly Featured Patents
Representation of designs
Method of condensing and/or polymerizing sulfonated lignin containing materials
Apparatus for determining horizontal and/or vertical permeability of an earth formation
System for monitoring cumulative fitness activity
Memory system and wear leveling method thereof
Belt fitting engagement rail
Method for processing and assembly of small parts utilizing a robot
Start-up system and method for switching voltage regulator
Waterproof clutches for sheet piles
Attaching method for a magnetic head used in a camera and attachment for the same