公开(公告)号：DE3689032T2

公开(公告)日：1994-04-14

申请号：DE3689032

申请日：1986-10-21

Applicant: IBM

Inventor： HWANG BAO TAI ,  ORR-ARIENZO WENDY ANN ,  GLANG REINHARD

IPC: H01L21/306 ,  H01L21/308

Abstract: The present invention provides an etchant composition and method for the resistivity specific etching of doped silicon films which overlie intrinsic or lightly doped crystal regions.The etchant comprises hydrofluoric acid, nitric acid, and acetic acid, the molecular ratio of nitric acid to hydrofluoric acid being greater than 2,0 and the mole percentage of nitric acid being greater than 14 mole %.The etchant leaves no silicon residue and provides for controlled etching with an etch stop at the lightly doped or intrinsic region.The method comprises the steps of:providing an etch mask overlying the silicon layer;immersing the doped silicon on the crystal surface in the etchant; andetching portions of the doped silicon layer exposed through the mask in the solution until the exposed doped silicon is removed and the underlying surface is clear and specular.

公开(公告)号：DE3689032D1

公开(公告)日：1993-10-21

申请号：DE3689032

申请日：1986-10-21

Applicant: IBM

Inventor： HWANG BAO TAI ,  ORR-ARIENZO WENDY ANN ,  GLANG REINHARD

IPC: H01L21/306 ,  H01L21/308

Abstract: The present invention provides an etchant composition and method for the resistivity specific etching of doped silicon films which overlie intrinsic or lightly doped crystal regions.The etchant comprises hydrofluoric acid, nitric acid, and acetic acid, the molecular ratio of nitric acid to hydrofluoric acid being greater than 2,0 and the mole percentage of nitric acid being greater than 14 mole %.The etchant leaves no silicon residue and provides for controlled etching with an etch stop at the lightly doped or intrinsic region.The method comprises the steps of:providing an etch mask overlying the silicon layer;immersing the doped silicon on the crystal surface in the etchant; andetching portions of the doped silicon layer exposed through the mask in the solution until the exposed doped silicon is removed and the underlying surface is clear and specular.