| 摘要 |
A method in a plasma processing chamber, for etching through a selected portion of an aluminum-containing layer and a titanium-containing layer. The titanium-containing layer is disposed above the aluminum-containing layer. The method includes a first etching step that etches at least partially through the titanium-containing layer using a first source gas composition. The first source gas composition consists essentially of the Cl2 etchant and a first mixture. The first mixture consists essentially of HCl and CHF3. The first source gas composition has a first flow ratio of the Cl2 etchant to the first mixture. There is further included a second etching step that etches at least partially through the aluminum-containing layer using a second source gas composition. The second source gas composition consists essentially of a Cl2 etchant and a second mixture. The second mixture consists essentially of HCl and CHF3. The second source gas composition has a second flow ratio of the Cl2 etchant to the second mixture different from the first flow ratio.
|
