Apparatus for fabricating a semiconductor structure and method of fabricating a semiconductor structure
The present disclosure provides a method for fabricating a semiconductor structure, including placing a wafer on a chuck, wherein the wafer is surrounded by a focus ring, the focus ring is supported by a first actuator, wherein the first actuator is in a cavity defined by the chuck and the edge ring, wherein the first actuator includes an outer ring disposed in the cavity, a piezoelectric layer apart from a top surface of the cavity, wherein an edge of the piezoelectric layer is fixed by the outer ring, and an inner ring disposed in the chamber at a center portion of the piezoelectric layer, performing plasma etch on a surface of the wafer, and controlling a distance between a gas distribution plate and a top surface of the focus ring to be less than a threshold value by the first actuator.
1 . A method for fabricating a semiconductor structure, comprising:
placing a wafer on a chuck, wherein the wafer is surrounded by a focus ring, the focus ring is supported by a first actuator, wherein the first actuator is in a cavity defined by the chuck and an edge ring, wherein the first actuator comprises:
an outer ring disposed in the cavity, wherein the outer ring is fixed to the edge ring, and a chamber is defined in the outer ring;
a piezoelectric layer apart from a top surface of the cavity, wherein an edge of the piezoelectric layer is fixed by the outer ring; and
an inner ring disposed in the chamber at a center portion of the piezoelectric layer, wherein the inner ring overlaps with the focus ring from a top view perspective;
performing plasma etch on a surface of the wafer; and
controlling a distance between a gas distribution plate (GDP) and a top surface of the focus ring to be less than a threshold value by the first actuator.
2 . The method of claim 1 , further comprising:
supplying gas through the GDP; and
increasing a gap height between a bottom surface of the focus ring and a top surface of the edge ring during the plasma etch.
3 . The method of claim 2 , further comprising increasing the gap height between bottom surface of the focus ring and the top surface of the edge ring according to a preset time schedule.
4 . The method of claim 2 , further comprising increasing the gap height between the bottom surface of the focus ring and the top surface of the edge ring according to a distance between the GDP and the top surface of the focus ring.
5 . The method of claim 4 , further comprising obtaining the distance by an acoustic transceiver.
6 . The method of claim 5 , wherein controlling the distance comprises adjusting a voltage supplied to the first actuator according to the distance obtained by the acoustic transceiver.
7 . The method of claim 2 , further comprising increasing the gap height between the bottom surface of the focus ring and the top surface of the edge ring according to a thickness of the focus ring.
8 . The method of claim 1 , wherein controlling the distance between the GDP and the top surface of the focus ring comprises: adjusting a power supplied to the first actuator, thereby a position of the center portion of the piezoelectric layer displaces.
9 . A method for fabricating a semiconductor structure, comprising:
placing a wafer on a chuck, wherein the wafer is surrounded by a focus ring, the focus ring is supported by a first actuator, wherein the first actuator is in a cavity defined by the chuck and an edge ring, wherein the first actuator comprises:
a piezoelectric layer, wherein a peripheral portion of the piezoelectric layer is fixed, and a bottom surface of the piezoelectric layer is apart from a first portion of the chuck and a first portion of the edge ring along a vertical direction;
a lift pin, placed over the piezoelectric layer; and
an inner ring, wherein the inner ring bears the lift pin, and the inner ring is at least partially surrounded by the piezoelectric layer laterally;
performing plasma etch on a surface of the wafer; and
adjusting a power supplied to the first actuator to adjust a vertical position of the center portion of the piezoelectric layer.
10 . The method of claim 9 , wherein the first actuator further comprises an insulation ring disposed in the cavity.
11 . The method of claim 10 , wherein the first portion of the chuck and the first portion of the edge ring are under a coverage of a vertical projection area of the insulation ring.
12 . The method of claim 10 , wherein the peripheral portion of the piezoelectric layer is fixed by the insulation ring.
13 . The method of claim 9 , further comprising controlling a distance between a gas distribution plate (GDP) and a top surface of the focus ring to be less than a threshold value by the first actuator.
14 . A method for fabricating a semiconductor structure, comprising:
placing a wafer on a chuck, wherein the wafer is surrounded by a focus ring, the focus ring is supported by a first actuator, wherein the first actuator is in a cavity defined by the chuck and an edge ring, wherein the first actuator comprises:
an outer ring disposed in the cavity, wherein the outer ring is fixed to the edge ring, and a chamber is defined in the outer ring;
a piezoelectric layer apart from a top surface of the cavity, wherein an edge of the piezoelectric layer is fixed by the outer ring; and
an inner ring disposed in the chamber at a center portion of the piezoelectric layer, wherein the inner ring overlaps with the focus ring from a top view perspective;
performing plasma etch on a surface of the wafer; and
adjusting a vertical position of the inner ring during the plasma etch.
15 . The method of claim 14 , further comprising replacing the focus ring with another focus ring according to a preset time schedule.
16 . The method of claim 14 , further comprising increasing a gap height between a bottom surface of the focus ring and a top surface of the edge ring during the plasma etch.
17 . The method of claim 14 , wherein the focus ring is detachable from the first actuator.
18 . The method of claim 14 , wherein the vertical position of the inner ring is adjusted by adjusting a power supplied to the first actuator.
19 . The method of claim 18 , wherein a magnitude of voltage of the power supplied to the first actuator is positively correlated to a counted period of time obtained by a timer.
20 . The method of claim 14 , wherein a pressure in the chamber is less than 100 mTorr.