METHOD FOR FORMING THIN FILM OF CRYSTALLINE MATERIAL SILICON NITRIDE COVERING IN SHALLOW TRENCH ISOLATION STRUCTURE AND SHALLOW TRENCH ISOLATION STRUCTURE FOR INTEGRATED CIRCUIT DEVICE OF SUB MICRON, AND CRYSTALLINE MATERIAL SILICON NITRIDE COVERING

摘要

PROBLEM TO BE SOLVED: To contain a trapping center with a lower density than before conversion, by depositing an Si₃N₄ covering with a specific thickness in an STI structure by the low-pressure chemical vapor deposition method, performing speedy heat annealing under specific conditions immediately after depositing the covering, and converting Si₃N₄ from amorphous to a crystal material. ;SOLUTION: After a shallow trench is etched, a thin thermal oxide with a thickness of approximately 10nm is grown to eliminate an etching damage. Then, an Si₃N₄ covering with a thickness of 5-10nm is deposited on the upper surface of an oxide layer in amorphous state at a temperature of 720-780°C in a shallow trench isolation structure(STI). Then, immediately after the covering is deposited, a high-speed heat annealing is executed nearly for 60 seconds at 1,050-1,150°C in pure nitrogen or ammonium and the Si₃N₄ covering is converted from the amorphous state to the crystal material state of a low- temperature-hexagonal (d) Si₃N₄ phase.;COPYRIGHT: (C)1998,JPO