| abstract |
In semiconductor device fabrication, tin oxide films are used as spacers and hard masks. In one method, a tin oxide layer is conformally formed on sidewalls and horizontal surfaces of protruding features on a substrate. A passivation layer is then formed on the tin oxide on the sidewalls, and the tin oxide is then removed from the horizontal surfaces of the protruding features, but not at the sidewalls of the protruding features. The material of the protruding features is then removed while leaving tin oxide residing at the sidewalls of the protruding features, thereby forming tin oxide spacers. Hydrogen-based dry etch chemistries and chlorine-based dry etch chemistries are used to selectively etch tin oxide in the presence of various materials. In another method, a patterned tin oxide hard mask layer is formed on a substrate by forming a patterned layer on unpatterned tin oxide and transferring the pattern onto the tin oxide. |