1. A reactor for removing polymer from a backside of a workpiece, comprising:
a vacuum chamber having a ceiling, a floor and a cylindrical side wall;
a workpiece support apparatus within said chamber configured for a workpiece to be placed thereon, wherein while being placed on the support apparatus, the workpiece has a front side facing said ceiling, said support apparatus configured to leave at least an annular periphery of the backside of said workpiece exposed;
a confinement member defining a narrow gap with an outer edge of said workpiece, said narrow gap being on the order of about 1% of the workpiece diameter, said narrow gap corresponding to a boundary dividing said chamber between an upper process zone and a lower process zone, said reactor further comprising a vacuum pump coupled to said lower process zone;
an external plasma-generating chamber coupled to the chamber, said external plasma-generating chamber configured to introduce a plasma by-product into said lower process zone, and a supply of a polymer etch precursor gas to said external plasma-generating chamber; and
said ceiling comprising a gas distribution plate facing said upper process zone, said reactor further comprising a purge gas supply coupled to said gas distribution plate.
2. The reactor of claim 1 wherein said confinement member comprises one of: (a) said side wall, (b) an annular ring surrounding said workpiece.
3. The reactor of claim 1 further comprising:
lift apparatus capable of lifting said support apparatus to a raised level of said boundary at which said upper process zone is confined to a height on the order of about 1% of the diameter of said chamber;
an upper slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said upper process zone and an upper zone vacuum pump coupled to said upper slit passage.
4. The reactor of claim 3 further comprising:
a lower slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said lower process zone and a lower zone vacuum pump coupled to said lower slit passage.
5. The reactor of claim 1 further comprising:
apparatus capable of lifting said support apparatus to a raised level of said boundary at which said upper process zone is confined to a height that is sufficiently small to limit gas residency time in said upper process zone to on the order of about 1% of gas residency time in said lower process zone;
an upper slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said upper process zone and an upper zone vacuum pump coupled to said upper slit passage.
6. The reactor of claim 5 further comprising:
a lower slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said lower process zone and a lower zone vacuum pump coupled to said lower slit passage.
7. The reactor of claim 1 wherein said support apparatus comprises one of: (a) a heated pedestal, (b) lift pins.
8. The reactor of claim 1 further comprising radiant lamps for heating the workpiece.
9. The reactor of claim 1 wherein said purge gas supply contains a non-reactive gas.
10. The reactor of claim 1 wherein said purge gas supply contains a scavenger of a polymer etch species.
11. The reactor of claim 1 further comprising plural conduits, each of said conduits coupled at one end to said external plasma generating chamber and having an opposite end comprising a gas outlet adjacent to and directed toward the periphery of the backside of said workpiece.
12. A reactor for removing polymer from a backside of a workpiece, comprising:
a vacuum chamber having a ceiling, a floor and a cylindrical side wall;
a workpiece support apparatus within said chamber and having a workpiece support surface defining a boundary between an upper process zone and a lower process zone of said chamber;
lift apparatus capable of lifting said support apparatus to a raised level of said boundary at which said upper process zone is confined to a height on the order of about 1% of the diameter of said chamber;
an upper slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said upper process zone and an upper zone vacuum pump coupled to said upper slit passage;
an external plasma-generating chamber coupled to introduce plasma by-products into said lower process zone, and a supply of a polymer etch precursor gas coupled to said external plasma-generating chamber; and
said ceiling comprising a gas distribution plate facing said upper process zone, said reactor further comprising a purge gas supply coupled to said gas distribution plate.
13. The reactor of claim 12 further comprising:
a lower slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said lower process zone and a lower zone vacuum pump coupled to said lower slit passage.
14. The reactor of claim 12 wherein said purge gas supply contains a non-reactive gas.
15. The reactor of claim 12 wherein said purge gas supply contains a scavenger of a polymer etch species.
16. The reactor of claim 12 further comprising plural conduits, each of said conduits coupled at one end to said external plasma generating chamber and having an opposite end comprising a gas outlet adjacent to and directed toward the periphery of the backside of said workpiece.
17. A reactor for removing polymer from a backside of a workpiece, comprising:
a vacuum chamber having a ceiling, a floor and a cylindrical side wall;
a workpiece support apparatus within said chamber and having a workpiece support surface defining a boundary between an upper process zone and a lower process zone of said chamber;
lift apparatus capable of lifting said support apparatus to a raised level at which said upper process zone is confined to a workpiece support surface-to-ceiling height that is sufficiently small to limit gas residency time in said upper process zone to on the order of 1% of gas residency time in said lower process zone;
an upper slit passage in said sidewall adjacent said boundary corresponding to said raised level and open exclusively into said upper process zone and an upper zone vacuum pump coupled to said upper slit passage.
an external plasma-generating chamber coupled to introduce plasma by-products into said lower process zone, and a supply of a polymer etch precursor gas coupled to said external plasma-generating chamber; and
said ceiling comprising a gas distribution plate facing said upper process zone, said reactor further comprising a purge gas supply coupled to said gas distribution plate.
18. The reactor of claim 17 wherein said purge gas supply contains a non-reactive gas.
19. The reactor of claim 17 wherein said purge gas supply contains a scavenger of a polymer etch species.
20. The reactor of claim 17 further comprising plural conduits, each of said conduits coupled at one end to said external plasma generating chamber and having an opposite end comprising a gas outlet adjacent to and directed toward the periphery of the backside of said workpiece.
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 method of conducting radio frequency (RF) communications between respective transceivers IN a communication network by transmitting on selected sub-channels contained within primary user channels of a prescribed RF communication band, said method comprising the steps of:
(a) monitoring said prescribed RF communication band for the presence of communication activity on said sub-channels, and identifying those ones of said sub-channels, which are effectively absent communication activity, as clear sub-channels that are potentially available for use by said respective transceivers; and
(b) causing said respective transceivers to conduct RF communications therebetween by controllably hopping among and transmitting on prescribed ones of said clear sub-channels in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said primary user channels.
2. The method according to claim 1, wherein step (b) further comprises distributing logically associated symbols among transmitted sub-channels.
3. The method according to claim 1, wherein step (b) further comprises successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
4. The method according to claim 1, wherein step (b) further comprises performing one or more of the following operations:
(a) distributing logically associated symbols among transmitted sub-channels, and
(b) successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
5. The method according to claim 4, wherein step (b) further comprises performing plural ones of said operations i-ii.
6. A method of conducting radio frequency (RF) communications between respective transceivers of a communication network by transmitting on selected sub-channels contained within primary user channels of a prescribed RF communication band, said method comprising the steps of:
(a) monitoring said prescribed RF communication band for the presence of communication activity on said sub-channels, and identifying sub-channels, which exhibit energy less than a prescribed value, as effectively clear sub-channels that are potentially available for use by said respective transceivers; and
(b) causing said respective transceivers to hop among and transmit on selected ones of said clear sub-channels in a manner that that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said primary user channels.
7. The method according to claim 6, wherein step (b) further comprises performing one or more of the following operations:
(a) distributing logically associated symbols among transmitted sub-channels, and
(b) successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
8. The method according to claim 7, wherein step (b) further comprises performing plural ones of said operations a and b.
9. The method according to claim 7, wherein step (b) further comprises distributing logically associated symbols among transmitted sub-channels.
10. The method according to claim 7, wherein step (b) further comprises successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
11. In a method of conducting radio frequency (RF) communications between respective spectral reuse transceivers of a communication network, wherein said transceivers monitor said prescribed RF communication band for the presence of communication activity on sub-channels contained within primary user channels of a prescribed RF communication band, and identify those sub-channels which exhibit energy less than a prescribed value, as effectively clear sub-channels that are potentially available for use by said respective spectral reuse transceivers, the improvement comprising the step of:
causing said respective spectral reuse transceivers to hop among and transmit on selected ones of said clear sub-channels in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said primary user channels.
12. The improvement according to claim 11, wherein further comprising performing one or more of the following operations:
(a) distributing logically associated symbols among transmitted sub-channels, and
(b) successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
13. The improvement according to claim 12, further comprising performing plural ones of operations a and b.
14. The improvement according to claim 13, wherein said transceivers are configured to exclude one or more prescribed sub-channels within said prescribed RF communication band for the presence of communication activity, in the course of identifying sub-channels, which exhibit energy less than said prescribed value, as effectively clear sub-channels that are potentially available for use by said respective spectral reuse transceivers, and wherein said causing step comprises causing said respective spectral reuse transceivers to hop among and transmit on selected ones of said clear sub-channels, that exclude said one or more prescribed sub-channels, in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said primary user channels.
15. A method of conducting radio frequency (RF) communications between respective transceivers of a communication network by transmitting on selected sub-channels contained within primary user channels of a prescribed RF communication band, said method comprising the step of:
(a) causing said respective transceivers to conduct RF communications therebetween by controllably hopping among and transmitting on prescribed ones of said sub-channels in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said primary user channels.
16. The method according to claim 15, wherein step (a) comprises distributing logically associated symbols among transmitted sub-channels.
17. The method according to claim 15, wherein step (a) comprises successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
18. A method of conducting radio frequency (RF) communications between respective transceivers of a communication network by transmitting on selected sub-channels, said method comprising the step of:
(a) causing said respective transceivers to hop among and transmit on selected ones of said sub-channels in a manner that that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said selected sub-channels.
19. The method according to claim 18 further comprising performing one or more of the following operations:
(a) distributing logically associated symbols among transmitted sub-channels, and
(b) successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
20. The method according to claim 18, further comprising performing plural ones of said operations a and b.
21. The method according to claim 20, further comprising distributing logically associated symbols among transmitted sub-channels.
22. The method according to claim 20, further comprising successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
23. In a method of conducting radio frequency (RF) communications between respective frequency-hopping transceivers of a communication network, the improvement comprising the step of:
causing said respective frequency-hopping transceivers to hop among and transmit on selected ones of said sub-channels in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said sub-channels.
24. The improvement according to claim 23, further comprising performing one or more of the following operations:
(a) distributing logically associated symbols among transmitted sub-channels, and
(b) successively hopping between and transmitting logically associated symbols in spectrally non-adjacent sub-channels.
25. The improvement according to claim 26, further comprising performing plural ones of operations a and b.
26. The improvement according to claim 26, wherein said frequency-hopping transceivers are configured to exclude one or more prescribed sub-channels, in a manner that reduces collisions of logically adjacent symbols to a degree that mitigates against reducing FEC circuit performance of receiving transceivers operating on said sub-channels.