Low-cost electrostatic clamp with fast de-clamp time
View Patent ↗A method for manufacturing a semiconductor wafer electrostatic clamp, comprising providing a mounting plate, forming an insulative layer on an insulating portion of the mounting plate, forming a first electrode on a first portion of the mounting plate, forming a second electrode on a second portion of the mounting plate, forming a first segment having a first conductivity over the first electrode, forming a first region having a second conductivity over the first segment that creates an n-p type composite, forming a second segment having a third conductivity formed over the over the second electrode, forming a second region having a fourth conductivity formed over the second region that creates an p-n type composite.
1. An electrostatic clamp system, comprising:
a first p-n junction semiconductor portion having a first p-type semiconductor segment overlying a first n-type semiconductor segment;
a second p-n junction semiconductor portion laterally disposed and electrically isolated from the first p-n junction semiconductor portion, the second p-n junction semiconductor portion having a second n-type semiconductor segment overlying a second p-type semiconductor segment;
a first conductive electrode underlying the first p-n junction semiconductor portion and electrically contacting the first n-type semiconductor segment; and
a second conductive electrode underlying the second p-n junction semiconductor portion and electrically contacting the second p-type semiconductor segment,
wherein the first and second conductive electrodes are electrically isolated from one another.
2. The electrostatic clamp system of claim 1 , further comprising a power supply system configured to apply concurrently a first voltage to the first conductive electrode, and a second voltage to the second conductive electrode.
3. The electrostatic clamp system of claim 2 , wherein the first voltage is different than the second voltage.
4. The electrostatic clamp system of claim 3 , wherein in a clamp system ON configuration, the first voltage is a positive voltage, and the second voltage is a negative voltage.
5. The electrostatic clamp system of claim 2 , wherein in a clamp system OFF configuration, the first and second voltages are the same voltage.
6. The electrostatic clamp system of claim 5 , wherein the first and second voltages equal 0V.
7. The electrostatic clamp system of claim 2 , wherein at least one of the first and second voltages applied by the power supply system comprises a time varying non-zero voltage value.
8. The electrostatic clamp system of claim 1 , wherein:
the first p-type semiconductor segment has a first surface facing the first n-type semiconductor segment, and a second, opposing surface forming a first clamp face portion configured to support a workpiece thereon; and
the second n-type semiconductor segment has a first surface facing the second p-type semiconductor segment, and a second, opposing surface forming a second clamp face portion configured to support the workpiece thereon.
9. The electrostatic clamp system of claim 8 , wherein the first and second clamp face portions are each unitary portions.
10. The electrostatic clamp system of claim 8 , wherein the first and second clamp face portions are each not unitary portions.
11. The electrostatic clamp system of claim 10 , wherein the first and second clamp face portions that are not unitary portions collectively form a checkerboard type pattern.
12. The electrostatic clamp system of claim 10 , wherein the first and second clamp face portions that are not unitary portions collectively form a pattern of alternating concentric rings.
13. The electrostatic clamp system of claim 1 , further comprising a dielectric support substrate upon which the first and second conductive electrodes reside.