Semiconductor device and formation method thereof
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChun-Ming Lung, Chung-Ting Ko, Ting-Hsiang Chang, Sung-En Lin, Chi On Chui
Life of this patent
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Abstract
A semiconductor device includes a fin structure, a metal gate stack, a barrier structure and an epitaxial source/drain region. The fin structure is over a substrate. The metal gate stack is across the fin structure. The barrier structure is on opposite sides of the metal gate stack. The barrier structure comprises one or more passivation layers and one or more barrier layers, and the one or more passivation layers have a material different from a material of the one or more barrier layers. The epitaxial source/drain region is over the barrier structure.
Claims20
A semiconductor device, comprising:
- a fin structure over a substrate;
- a metal gate stack across the fin structure;
- a barrier structure on opposite sides of the metal gate stack, wherein the barrier structure comprises one or more passivation layers and one or more barrier layers, and the one or more passivation layers have a material different from a material of the one or more barrier layers, at least one of the one or more barrier layers is enclosed in the one or more passivation layers in a cross-sectional view;
- and
- an epitaxial source/drain region over the barrier structure.
A method of forming a semiconductor device, comprising:
- patterning a substrate to form a fin over the substrate;
- recessing the fin to form a source/drain recess;
- forming a passivation layer extending along a sidewall and directly over a bottom of the source/drain recess;
- performing a deposition process to form a barrier layer on the passivation layer, wherein the barrier layer has a different etch selectivity than the passivation layer;
- and
- forming an epitaxial source/drain region over the barrier layer and the passivation layer, wherein the epitaxial source/drain region interfaces with a top of the passivation layer at a first level and interfaces with a top of the barrier layer at a second level different from the first level.
A method of forming a semiconductor device, comprising:
- forming a fin over a substrate, the fin comprising alternately stacked first semiconductor layers and second semiconductor layers;
- forming a gate stack crossing the fin;
- repeating a deposition cycle to form a barrier structure on opposite sides of the gate stack, the deposition cycle comprising:
- conformally forming a passivation layer on the gate stack, the fin and the substrate, wherein the passivation layer includes a top portion over a top surface of the gate stack, a bottom portion in contact with the substrate, and a lateral portion extending along a sidewall of the fin and a sidewall of the gate stack;
- forming a barrier layer on the top portion and the bottom portion of the passivation layer;
- and
- removing the lateral portion of the passivation layer;
- and
- forming an epitaxial source/drain region on the opposite sides of the gate stack.
Dependencies are inferred from the claim text.