Gibb & Rahman, LLC
Post-silicide spacer removal
A method forms a gate conductor over a substrate, forms spacers (e.g., nitride spacers) on sides of the gate conductor, and implants an impurity into exposed regions of the substrate not protected by the gate conductor and the spacers. Then the method forms a silicide on surfaces of the exposed regions of the substrate. The method forms a conformal protective layer (e.g., an oxide or other similar material) over the silicide, the spacers, and the gate conductor. Next, the method forms a non-conformal sacrificial layer (e.g., nitride or other material that can be selectively removed with respect to the protective layer) over the protective layer. A subsequent partial etching process partially etches the sacrificial layer such that relatively thinner regions of the sacrificial layer that are over the spacers are completely removed and the relatively thicker regions of the sacrificial layer that are over the substrate are not removed. The next step in the method removes only those portions of the protective layer that cover the spacers, without removing the portions of the protective layer that cover the silicide. As the spacers are now exposed and the silicide is protected by the protective and sacrificial layers, the method can safely remove the spacers without affecting the silicide.
Chartered Semiconductor Manufacturing, Ltd. Infineon Technologies North America Corporation Samsung Electronics Co. Ltd. International Business Machines Corporation
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inventional additional additional inventional
Thomas W. Yong Meng JunJung Siddhartha Sunfei Jiang
Dyer Lee Kim Panda Fang Yan