1. A debris mitigation device for use with a radiation source (2) generating optical radiation, and emitting undesired substances andor particles, said debris mitigation device comprising
a rotating foil trap (5) and
a drive unit comprising a casing, at least a driving motor (14) and a driving axis (10), to which said rotating foil trap (5) is fixed outside of said casing, said driving axis (10) being supported by lubricated bearings (13),
wherein said driving motor (14) and said bearings (13) are enclosed in said casing (20) having an aperture for said driving axis (10) and at least one outlet opening (21) for a sealing gas, said outlet opening (21) being connectable to a pump for pumping out the sealing gas, said aperture being designed to define a gap (23) between said driving axis (10) and said casing (20), said gap (23) being connected to a supply pipe (19) for supplying said sealing gas through said gap (23) into said casing (20).
2. The device according to claim 1, wherein a lead-through for said driving axis (10) is arranged between said rotating foil trap (5) and said casing (20), said lead-through being designed to form a further gap (33) between said driving axis (10) and a surrounding wall, said further gap (33) being connected to said supply pipe (19) together with said gap (23) between said driving axis (10) and said casing (20).
3. The device according to claim 2, wherein said debris mitigation device further comprises a static foil trap (4) which is arranged between said rotating foil trap (5) and said driving unit.
4. The device according to claim 3, wherein said lead-through is formed in said static foil trap (4).
5. The device according to claim 3, wherein said lead-through extends into an intermediate space formed between said rotating foil trap (5) and said static foil trap (4).
6. The device according to claim 2, wherein said surrounding wall defines a pumping space (26) to said further gap (33), said pumping space (26) being connected to a pumping pipe (27), which is connectable to a pump for pumping out the sealing gas.
7. The device according to claim 1, wherein said gap (23) between said driving axis (10) and said casing (20) has a gap width smaller than 200 \u03bcm.
8. The device according to claim 2, wherein said further gap (33) between said driving axis (10) and said surrounding wall has a gap width smaller than 100 \u03bcm.
9. The device according to claim 1, wherein said drive unit comprises a check valve (29) in said casing (20), said check valve (29) being designed and arranged to close said gap (23) between said driving axis (10) and said casing (20) if a flow of said sealing gas through said gap (23) is interrupted.
10. The device according to claim 9, wherein said check valve (29) is designed and arranged to automatically close said gap (23) due to pressure differences arising if the flow of said sealing gas through said gap (23) is interrupted or due to the action of an elastic element attached to a movable component (30) of the check valve (29).
11. A drive assembly, comprising
a casing,
a driving motor (14), and
a driving axis (10) for driving a component arranged outside of said casing, said driving axis (10) being supported by lubricated bearings (13), wherein said driving motor (14) and said bearings (13) are enclosed in said casing (20) having an aperture for said driving axis (10) and at least one outlet opening (21) for a sealing gas, said outlet opening (21) being connectable to a pump for pumping out the sealing gas, said aperture being designed to define a gap (23) between said driving axis (10) and said casing (20), said gap (23) being connected to a supply pipe (19) for supplying said sealing gas through said gap (23) into said casing (20).
12. The drive assembly according to claim 11, wherein a lead-through for said driving axis (10) is arranged between said component and said casing (20), said lead-through being designed to form a further gap (33) between said driving axis (10) and a surrounding wall, said further gap (33) being connected to said supply pipe (19) together with said gap (23) between said driving axis (10) and said casing (20).
13. The drive assembly according to claim 12, wherein said surrounding wall comprises a pumping space (26) to said further gap (33), said pumping space (26) being connected to a pumping pipe (27), which is connectable to a pump for pumping out the sealing gas.
14. The drive assembly according to claim 11, wherein said gap (23) between said driving axis (10) and said casing (20) has a gap width smaller than 200 \u03bcm.
15. The drive assembly according to claim 11, further comprising a check valve (29) in said casing (20), said check valve (29) being designed and arranged to close said gap (23) between said driving axis (10) and said casing (20) if a flow of said sealing gas through said gap (23) is interrupted.
16. The drive assembly according to claim 15, wherein said check valve (29) is designed and arranged to automatically close said gap due to pressure differences arising if the flow of said sealing gas through said gap (23) is interrupted or due to the action of an elastic element attached to an movable component (30) of the check valve (29).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A high-mobility vertical trench DMOS, comprising:
a trenched gate;
a top source region disposed next to the trenched gate;
a bottom drain region disposed below the bottom of the trenched gate; and
a channel region proximate to a sidewall of the trenched gate between the source and drain regions
wherein at least one of the channel region, source region and drain region comprises SiGe configured to increase the mobility of charge carriers in the channel region.
2. A high-mobility vertical trench DMOS, comprising:
a trenched gate;
a top source region disposed next to the trenched gate;
a bottom drain region disposed below the bottom of the trenched gate; and
a channel region proximate to a sidewall of the trenched gate between the source and drain regions;
wherein the channel region is strained to increase channel charge carriers mobility.
3. The high-mobility vertical trench DMOS of claim 2 wherein the channel region comprises SiGe.
4. The high-mobility vertical trench DMOS of claim 3 wherein the channel region includes P-type SiGe.
5. The high-mobility vertical trench DMOS of claim 4, wherein the drain region comprises SiGe.
6. The high-mobility vertical trench DMOS of claim 5, wherein the drain region includes N-type SiGe.
7. The high-mobility vertical trench DMOS of claim 2, wherein the source region comprises SiGe.
8. The high-mobility vertical trench DMOS of claim 7, wherein the source region includes an N+ strained SiGe source.
9. The high-mobility vertical trench DMOS of claim 8, wherein the drain region comprises SiGe.
10. The high-mobility vertical trench DMOS of claim 9, wherein the drain region includes N-type SiGe.
11. A method for manufacturing a high-mobility vertical trenched DMOS comprising:
a) forming an N-type epitaxial (N-epi) layer on top of the N+ substrate;
b) forming a trench mask on top of the N-epi layer;
c) etching the N-epi layer through the trench mask to a predetermined depth to form a trench;
d) filing the trench with a conductive material to form a gate; and
e) forming SiGe region proximate to the gate, wherein the SiGe region configured to increase a mobility of charge carriers in a channel region.
12. The method of claim 11 wherein step e) is performed before step d).
13. The method of claim 11 further comprising forming a P-body layer on the surface of the N-epi layer
14. The method of claim 13, wherein step e) comprises:
depositing an undoped SiGe layer with a predetermined depth on a sidewall and a bottom of the trench;
implanting N-type dopants in the deposited undoped SiGe portion at the bottom of the trench; and
annealing the deposited SiGe layer.
15. The method of claim 14 further comprising forming a gate oxide layer on the gate between step d) and step e).
16. The method of claim 13, wherein step e) comprises:
growing a thin oxide layer in the trench;
forming a nitride layer over the thin oxide layer;
partially etching the nitride layer to form nitride spacer;
etching a portion of the thin oxide layer at a bottom of the trench;
etching at least a portion of the N-epi layer to a predetermined depth;
forming a thick oxide layer on the portion of the N-epi layer that was etched;
removing the nitride spacer and thin oxide layer from a sidewall of the trench;
growing P-type SiGe on the sidewall of the trench;
etching back the thick oxide layer; and
forming a gate oxidation layer on the P-type SiGe on the sidewall of the trench.
17. The method of claim 13, wherein step e) comprises:
forming an oxide spacer on the trench sidewall;
isotropically etching a portion of the N-epi layer at a bottom of the trench;
selectively growing an N-type SiGe region on the portion of the N-epi layer that was isotropically etched;
etching the oxide spacer and the trench mask; and
forming a gate oxide layer on the N-type SiGe on the sidewall of the trench.
18. The method of claim 13, wherein step e) comprises:
depositing undoped SiGe into the trench;
forming an oxide layer on top of the undoped SiGe layer;
etching back the oxide layer at a bottom of the trench to expose a portion of the undoped SiGe and to form an oxide spacer on a sidewall of the trench;
etching a portion of the undoped SiGe layer at the bottom of the trench to expose an underlying portion of the N-epi layer;
isotropically etching the undoped SiGe layer and the N-epi layer at the bottom of the trench;
removing the oxide spacer from the sidewall; and
forming a gate oxide in the trench over the bottom of the trench and over the undoped SiGe layer on the sidewall of the trench.
19. The method of claim 11 wherein step d) is performed before step e).
20. The method of claim 19 further comprising, before step d):
removing the trench mask; and
forming a gate oxide on the gate.
21. The method of claim 20, further comprising: after step e):
implanting and diffusing the top region of the N-epi layer to form P-body layer; and
forming a poly oxide layer on top of the gate; and
etching the oxide layer on top of the P-body layer.
22. The method of claim 21, wherein step e) comprises:
selectively growing N+ SiGe region on top of the P-body layer; and
etching back the N+ SiGe region to a predetermined width to form a source region.
23. The method of claim 19 further comprising forming a gate oxide before step d).
24. The method of claim 23 further comprising after step d):
implanting and diffusing a top region of the N-epi layer to form a P-body layer;
removing the trench mask; and
forming an oxide layer over the gate.
25. The method of claim 24, wherein step e) comprises:
selectively growing N+ SiGe region on top of the P-body layer; and
etching back the N+ SiGe region to a predetermined width to form a source region.