公开(公告)号：DE10149736C1

公开(公告)日：2003-04-17

申请号：DE10149736

申请日：2001-10-09

Applicant: INFINEON TECHNOLOGIES AG

Inventor： HOEHNSDORF FALKO ,  BACHMANN JENS ,  BAIER ULLRICH

IPC: H01L21/3213 ,  H01L21/768

Abstract: Etching of metal layer systems comprises providing a semiconductor wafer with at least two aluminum-containing layers consisting of an upper aluminum-containing layer (3) separated from a lower aluminum-containing layer (2) by an intermediate layer (5), and etching of the upper aluminum- containing layer with a first etching angle followed by etching of the lower aluminum- containing layer with a second etching angle different to the first etching angle. A switch is made between the first and the second etching steps as soon as an end point determination identifies that the intermediate layer has been reached. Preferred Features: The first etching step is carried out at a higher etching rate than the second etching step. The etching gas is a mixture of BCl3 and Cl2. During the second etching step the mixture contains a greater quantity of BCl3 and a smaller quantity of Cl2 than the mixture used for the first etching step. The etching gas also contains CH4 and N2. The intermediate layer is a titanium or TiN layer.