Devices and methods for deposition
View Patent ↗Devices and methods for performing physical vapor deposition (PVD) include a process chamber. The process chamber includes a wafer holder, an annular shield with a vertical sidewall around a central opening, a clamp having a plurality of alignment pins extending from the lower surface and passing through the pin openings in the annular shield; and a heater configured to pass through the central aperture of the wafer holder. Each alignment pin may have a length such that a lower end of the alignment pin does not contact the annular shield at a process position where the heater and the clamp engage the associated wafer substrate and the hoop does not engage the clamp. The clamp may include a groove that engages the vertical sidewall of the annular shield in a release or rest position.
1 . A method for improving deposition uniformity across a wafer substrate, comprising:
placing the wafer substrate upon a wafer holder in a release position;
raising the wafer holder from the release position through a central opening in an annular shield to a lift position where the wafer holder engages a clamp;
raising a heater through a central aperture in the wafer holder to lift the wafer substrate off the wafer holder and up to a process position where the heater and the clamp engage the associated wafer substrate and the wafer holder does not engage the clamp;
depositing a material layer upon the wafer substrate.
2 . The method of claim 1 , wherein the material layer is deposited by sputtering from a target above the wafer substrate.
3 . The method of claim 1 , wherein the material layer is deposited by evaporation from a target above the wafer substrate.
4 . The method of claim 1 , wherein the clamp comprises a ring body having a lower surface, and a plurality of alignment pins extending from the lower surface; and
wherein the plurality of alignment pins passes through a plurality of pin openings in the annular shield;
wherein each alignment pin has a length such that a lower end of the alignment pin does not contact the annular shield at the process position.
5 . The method of claim 1 , wherein the clamp further comprises a groove in a lower surface thereof, and the groove engages a vertical sidewall of the annular shield in the release position.
6 . The method of claim 1 , wherein the wafer holder comprises a hoop body around the central aperture.
7 . The method of claim 6 , wherein the wafer holder further comprises support fingers extending upwards from the hoop body.
8 . The method of claim 1 , further comprising applying a bias voltage to the clamp.
9 . A method for performing deposition upon a wafer substrate, comprising:
receiving the wafer substrate in a device that comprises:
a wafer holder for holding the wafer substrate, comprising a hoop body around a central aperture;
an annular shield comprising a lower surface with a plurality of pin openings therein and a vertical sidewall around a central opening;
a clamp comprising a ring body having a lower surface with a groove that engages the vertical sidewall in a release position, and a plurality of alignment pins extending from the lower surface and passing through the plurality of pin openings; and
a heater configured to pass through the central aperture of the hoop;
raising the wafer holder from the release position to a lift position where the wafer holder engages the clamp;
raising the heater through the central aperture in the wafer holder to lift the wafer substrate to a process position where the heater and the clamp engage the wafer substrate and the hoop does not engage the clamp; and
depositing a material layer upon the wafer substrate.
10 . The method of claim 9 , further comprising:
lowering the wafer substrate from the process position to the lift position; and
lowering the wafer holder from the lift position to the release position.
11 . A method for performing deposition upon a wafer substrate, comprising:
raising a wafer holder holding the wafer substrate from a release position through a central opening in an annular shield to a lift position where the wafer holder engages a clamp;
raising a heater through a central aperture in the wafer holder to lift the wafer substrate off the wafer holder and up to a process position where the heater and the clamp engage the associated wafer substrate and the wafer holder does not engage the clamp;
depositing a material layer upon the wafer substrate.
12 . The method of claim 11 , wherein the material layer is deposited by sputtering from a target above the wafer substrate or by evaporation from a target above the wafer substrate.
13 . The method of claim 11 , wherein the clamp comprises a ring body having a lower surface, and a plurality of alignment pins extending from the lower surface; and
wherein the plurality of alignment pins passes through a plurality of pin openings in the annular shield;
wherein each alignment pin has a length such that a lower end of the alignment pin does not contact the annular shield at the process position.
14 . The method of claim 13 , wherein each alignment pin is electrically insulated.
15 . The method of claim 11 , wherein the clamp further comprises a groove in a lower surface thereof, and the groove engages a vertical sidewall of the annular shield in the release position.
16 . The method of claim 15 , wherein the groove has a width of about 5 mm or less.
17 . The method of claim 15 , wherein the vertical sidewall of the annular shield has a height of about 2 cm to about 8 cm.
18 . The method of claim 11 , wherein the wafer holder comprises a hoop body around the central aperture.
19 . The method of claim 18 , wherein the wafer holder further comprises support fingers extending upwards from the hoop body.
20 . The method of claim 11 , further comprising applying a bias voltage to the clamp.