Etch resistant shallow trench isolation in a semiconductor wafer
AssigneeLSI Logic Corporation
InventorsRajiv Patel, David Chan, Arvind Kamath, Ken Rafftesaeth, Venkatesh P. Gopinath
Life of this patent
Estimating the term…
Abstract
A shallow isolating trench is formed in a semiconductor wafer between active component areas to electrically isolate the active components from each other. The isolating trench is primarily formed of an insulating material, such as an oxide, in a recess formed into the wafer. An etch resistant material, such as BTBAS nitride, is placed over the insulating material in the recess. The etch resistant material protects the insulating material from erosion due to subsequent semiconductor fabrication process steps, so the integrity of the isolating trench and the planarity of the wafer are generally maintained.
Claims11
A method for forming an isolating trench between active areas in a semiconductor substrate comprising the steps of:
- providing a semiconductor substrate having a top surface and at least two regions for active areas;
- forming a recess for the isolating trench in the top surface of the semiconductor substrate between the two regions;
- placing an insulating material into the recess to form a primary portion of the isolating trench between the two regions;
- and
- placing a Bis-Tertiary-Butyl-Amino-Silane nitride layer that is etch resistant to a hot phosphoric acid etch over the insulating material of the isolating trench.
An electrically isolating trench between electrically active areas of an integrated circuit formed in a semiconductor substrate by steps including an application of a hot phosphoric acid etch substance comprising:
- a recess formed between the active areas in the semiconductor substrate;
- an insulating material disposed in the recess to form a primary portion of the isolating trench, the insulating material being substantially reactive with the hot phosphoric acid etch substance and substantially preventing electrical interference between the active areas;
- and
- a Bis-Tertiary-Butyl-Amino-Silane nitride etch resistant material overlaying the insulating material and being substantially unreactive with the hot phosphoric acid etch substance.
Dependencies are inferred from the claim text.