Fabricating contacts of a CMOS structure
The invention relates to a method comprising providing a substrate with a channel layer, forming a gate stack structure on the channel layer and forming a raised source and a raised drain on the channel layer. The method further comprises depositing in a non-conformal way an oxide layer above the gate stack structure, the raised source and the raised drain. A first void above the raised source and a second void above the raised drain gate are created adjacent to vertical edges of the gate stack structure. The method further comprises etching the oxide layer for a predefined etching time, thereby removing the oxide layer above the raised source and the raised drain, while keeping it at least partly on the channel layer. Contacts are formed to the raised source and the raised drain. The invention also concerns a corresponding computer program product.
1. A computer program product, comprising:
a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to cause one or more semiconductor processing apparatus to perform at least the following:
forming a gate stack structure on a channel layer of a substrate;
forming a raised source and a raised drain on the channel layer;
depositing in a non-conformal way an oxide layer above the gate stack structure, the raised source and the raised drain, thereby creating a first void above the raised source and a second void above the raised drain adjacent to vertical edges of the gate stack structure;
etching the oxide layer for a predefined etching time, thereby removing the oxide layer above the raised source and the raised drain, while keeping it at least partly on the channel layer; and
forming contacts to the raised source and the raised drain.