Retention time improvement by fast-pull and fast-cool (FPFC) ingot growing combined with proper arrangement of subsequent thermal budget for 0.18 /spl mu/m DRAM cell and beyond

Abstract

The denudation scheme based on vacancy-assisted BMD (bulk micro defect) formation for reducing grown-in defects and the method of reducing STI-stress caused by denudation thermal budget was investigated to improve the retention time of high density DRAM with STI (shallow trench isolation). In this paper, we report the denudation scheme employing low-cost FPFC (fast-pull and fast-cool) ingot growth, combined with proper arrangement of subsequent thermal budget, resulting in excellent improvement of DRAM retention time.