Mosfet device structure with air-gaps in spacer and methods for forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsGulbagh Singh, Kun-Tsang Chuang, Po-Jen Wang
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Abstract
A transistor device and method of making the same are disclosed. The transistor device includes one or more air gaps in one or more sidewall spacers. The one or more air gaps may be located adjacent the gate and/or above the source or drain regions of the device. Various embodiments may include different combinations of air gaps formed in one or both sidewall spacers. Various embodiments may include air gaps formed in one or both sidewall spacers adjacent to the gate and/or above the source or drain regions of the device. The formation of the air gaps may reduce unwanted parasitic and/or fringing capacitance.
Claims20
A semiconductor device, comprising:
- a gate on a substrate;
- a silicide layer on the gate;
- and
- a sidewall spacer on a sidewall of the gate, comprising:
- a first oxide layer contacting the sidewall of the gate and having an upper surface substantially aligned with an upper surface of the silicide layer;
- a nitride layer on the first oxide layer, wherein the first oxide layer extends beyond the nitride layer;
- and
- a second oxide layer on the nitride layer and including an arc-shaped surface having a first end substantially aligned with the upper surface of the first oxide layer.
A method of forming a semiconductor device, comprising:
- forming a gate on a substrate;
- forming a source/drain region in the substrate on a side of the gate;
- depositing a first oxide material on the gate and the substrate;
- depositing a nitride material on the first oxide material;
- depositing a second oxide material on the nitride material;
- etching the first oxide material, nitride material and second oxide material to form a sidewall spacer on a sidewall of the gate, wherein the sidewall spacer comprises:
- a first oxide layer contacting the sidewall of the gate;
- a nitride layer on a side of the first oxide layer;
- and
- a second oxide layer on the nitride layer and including an arc-shaped surface having a first end substantially aligned with an upper surface of the first oxide layer;
- forming a silicide layer on the gate such that the upper surface of the first oxide layer is substantially aligned with an upper surface of the silicide layer;
- and
- etching the nitride layer such that the first oxide layer extends beyond the nitride layer.
A semiconductor device, comprising:
- a gate on a substrate;
- a silicide layer on the gate;
- and
- a sidewall spacer on a side of the gate, comprising:
- a first oxide layer contacting the side of the gate and having a first oxide upper portion surface substantially aligned with an upper surface of the silicide layer;
- and
- a nitride layer on a side of the first oxide upper portion, wherein the first oxide layer extends beyond an upper surface of the nitride layer;
- and
- an etch resistant layer on the sidewall spacer, wherein a bottom surface of the etch resistant layer is separated from the upper surface of the nitride layer by a gap.
Dependencies are inferred from the claim text.