Semiconductor device and method of manufacture
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChun-Yi Lee, Hong-Hsien Ke, Chung-Ting Ko, Chia-Hui Lin, Jr-Hung Li
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Abstract
An etch stop layer is formed over a semiconductor fin and gate stack. The etch stop layer is formed utilizing a series of pulses of precursor materials. A first pulse introduces a first precursor material to the semiconductor fin and gate stack. A second pulse introduces a second precursor material, which is turned into a plasma and then directed towards the semiconductor fin and gate stack in an anisotropic deposition process. As such, a thickness of the etch stop layer along a bottom surface is larger than a thickness of the etch stop layer along sidewalls.
Claims20
A method of manufacturing a semiconductor device, the method comprising:
- forming spacers adjacent to a gate stack over a semiconductor fin;
- and
- depositing an etch stop layer over the gate stack and adjacent to the spacers, the depositing the etch stop layer comprising:
- pulsing a first precursor over the gate stack a first time, the first precursor being a non-plasma;
- after the pulsing the first precursor, pulsing a second precursor over the gate stack a first time, the second precursor being a plasma biased towards the semiconductor fin, the etch stop layer having a first thickness adjacent to the spacers and a second thickness larger than the first thickness over the gate stack, the plasma bias causing a growth rate boost to a portion of the etch stop layer, the etch stop layer comprising silicon nitride, wherein the first precursor is diiodosilane and the second precursor is nitrogen;
- after the pulsing the second precursor, pulsing the first precursor a second time;
- and
- after the pulsing the first precursor the second time, pulsing the second precursor a second time, wherein the pulsing the second precursor is performed at a different RF power than the pulsing the second precursor the first time.
A method of manufacturing a semiconductor device, the method comprising:
- forming a first gate stack and a second gate stack over a semiconductor fin;
- forming a first spacer adjacent to the first gate stack and a second spacer adjacent to the second gate stack;
- pulsing a first precursor to react in a self-limiting reaction to form a first reaction product on a surface of the first gate stack and a surface of the first spacer;
- anisotropically pulsing a first plasma towards the first reaction product to form a first monolayer of a first material;
- repeating the pulsing the first precursor and the anisotropically pulsing the first plasma to form an etch stop layer of the first material, wherein each repetition has a different RF power, the etch stop layer having a first thickness adjacent to the first spacer and a second thickness larger than the first thickness over the first gate stack;
- and
- etching the etch stop layer to form a third spacer adjacent to the first spacer, the third spacer comprising silicon nitride, wherein the first precursor is diiodosilane and the first plasma is a nitrogen plasma.
A method of manufacturing a semiconductor device, the method comprising:
- placing a substrate having a first spacer adjacent to a gate stack over a semiconductor fin into a deposition chamber;
- performing a first step comprising pulsing diiodosilane into the deposition chamber;
- purging the deposition chamber after the first step;
- performing a second step comprising:
- pulsing nitrogen into the deposition chamber;
- igniting the nitrogen into a plasma;
- and
- directing the plasma towards the substrate using a directional bias;
- and
- repeating the first step and the second step to build a layer of silicon nitride, wherein a first repetition has a first RF power and a second repetition has a second RF power different from the first RF power.
Dependencies are inferred from the claim text.