Title :
Elimination of notch during gate polycide stack etching by adding nitrogen in over etch step
Author :
Chan, Bor-Wen ; Liou, Y.H. ; Chi, Min-Hwa
Author_Institution :
Technol. Dev. Centre, Worldwide Semicond. Manuf. Corp., Hsinchu, Taiwan
Abstract :
In this paper, the notch phenomenon in sub-quarter-micron DRAM polycide gate etching process is an important issue and is improved by adding N2 gas in the step of over-etch (OE). The critical dimension (CD) after etching and remaining oxide (REOX) is almost the same by using various small amount of N2 flow rate in our study. However, there are residues found around the corner of active area (AA) if too much N2 gas added; however, the residue can be removed by increasing the OE time of WSix etching
Keywords :
DRAM chips; sputter etching; N2; N2 gas; WSi; active area; critical dimension; gate polycide stack etching; notch elimination; over etch step; remaining oxide; sub-quarter-micron DRAM polycide gate etching process; Etching; Fabrication; Nitrogen; Plasma applications; Plasma density; Plasma devices; Plasma materials processing; Plasma sources; Radio frequency; Random access memory;
Conference_Titel :
Plasma Process-Induced Damage, 2000 5th International Symposium on
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-9651577-4-1
DOI :
10.1109/PPID.2000.870594
