고밀도 $Cl_2/HBr$ 플라즈마에 의한 비도핑 $\alpha$-Si 식각시 나칭 현상

Notching Effect in Etching of the Undoped $\alpha$-Si by using High Density $Cl_2/HBr$ Plasma

The notching effect in etching of un doped amorphous silicon gate had different characteristics and mechanism comparing with reported ones. The undoped amorphous silicon was etched by using HBr gas plasma, First, in the region of small line width, the potential was increased as a result of ions in the exposed surface of oxide, and the incident ions between the small line width were deflected more wide range, therefore the depth of notching was shallow and wide, Second, in the region of large line width of gate, electrons were charged on the top of photoresist and the side of gate, a part of ions deflected, The deflected ions were locally charged positive on the side of gate, and then the potential difference was produced, therefore, ions stored up more at independent line than at dense line, and nothing became deeper by Br ion bombardment.