Retention time improvement by fast-pull and fast-cool (FPFC) ingot growing combined with proper arrangement of subsequent thermal budget for 0.18 μm 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 FPFCIFast-Pull and Fast-Cool] ingot growing, combined with proper arrangement of subsequent thermal budget, resulting in excellent improvement of DRAM retention time.