US5770099A — Plasma etch apparatus with heated scavenging surf…

Claim 1

Independent Claim 109 words

A method of operating a plasma reactor, comprising: inductively coupling RF energy into the reactor; introducing a fluorine-carbon containing gas into said reactor which disassociates as a plasma into an etch species which is capable of etching oxide films on a work piece in the reactor and a non-etching species combinable with the etch species into an etch-preventing polymer condensable onto an interior wall of the reactor and areas of the work piece; and maintaining a temperature of said interior wall above a characteristic deposition temperature of said etch-preventing polymer to control condensation of said polymer on said interior wall whenever said plasma is not present in the reactor.

Claim 2

Independent Claim 109 words

A method of operating a plasma reactor, comprising: inductively coupling RF energy into the reactor; introducing a fluorine-carbon containing gas into said reactor which disassociates as a plasma into an etch species which is capable of etching oxide films on a work piece in the reactor and a non-etching species combinable with the etch species into an etch-preventing polymer condensable onto an interior wall of the reactor and areas of the work piece; and maintaining a temperature of said interior wall above a characteristic deposition temperature of said etch-preventing polymer to control condensation of said polymer on said interior wall whenever said plasma is not present in the reactor.

Claim 3

Dependent Claim 21 words

The method of claim 1, wherein the interior wall is maintained at a temperature between about 170 and 230 degrees C.

Claim 4

Dependent Claim 23 words

The method of claim 1, wherein the temperature maintaining step comprises adding heat energy to said interior wall from an outside heat source.

Claim 5

Dependent Claim 21 words

The method of claim 3, wherein the temperature maintaining step further comprises cooling said interior wall with an outside cooling source.

Claim 6

Dependent Claim 18 words

The method of claim 1, wherein the temperature maintaining step comprises both heating and cooling said interior wall.

Claim 7

Dependent Claim 14 words

The method of claim 1, further comprising providing a fluorine scavenger within the reactor.

Claim 8

Dependent Claim 11 words

The method of claim 6, wherein said fluorine scavenger comprises silicon.

Claim 9

Dependent Claim 15 words

The method of claim 1 wherein said material which scavenges comprises a material containing silicon.

Claim 10

Dependent Claim 11 words

The method of claim 2 wherein said material comprises crystalline silicon.

Claim 11

Dependent Claim 10 words

The method of claim 2 wherein said material comprises quartz.

Claim 12

Dependent Claim 23 words

The method of claim 1 wherein said maintaining comprises maintaining said temperature in a range from about 170° C. to about 230° C.

Claim 13

Dependent Claim 23 words

The method of claim 1 wherein said maintaining comprises maintaining said temperature in a range from about 200° C. to about 300° C.

Claim 14

Dependent Claim 24 words

The method of claim 1 wherein said maintaining comprises transferring heat to said interior surface, said heat being derived from an outside heat source.

Claim 15

Dependent Claim 24 words

The method of claim 1 wherein said maintaining comprises transferring cooling to said interior surface, said cooling being derived from an outside cooling source.

Claim 16

Dependent Claim 29 words

The method of claim 1 wherein said maintaining comprises transferring cooling an heat to said interior surface, said cooling and heat being derived from outside cooling and heat sources.

Claim 17

Dependent Claim 43 words

The method of claim 1 wherein said maintaining step comprises: providing a heating element near said reactor; and applying sufficient power to said heating element so as to maintain the temperature of said interior surface above said threshold temperature by a predetermined difference.

Claim 18

Dependent Claim 32 words

The method of claim 9 wherein said sufficient power is a function of a difference between a temperature measured on a portion of said reactor and a temperature predetermined for that portion.

Claim 19

Dependent Claim 15 words

The method of claim 10 wherein said portion is an outer surface of said reactor.

Claim 20

Dependent Claim 36 words

The method of claim 1 wherein said maintaining comprises maintaining a temperature of said interior surface at a temperature corresponding to a desired content ratio of said non-etching species and said etching species in said plasma.

Claim 21

Dependent Claim 40 words

The method of claim 12 wherein said desired content ratio in said plasma corresponds to a content ratio of said non-etching species in said polymer at which said polymer is impervious to attack by said etching species in said plasma.

Claim 22

Dependent Claim 18 words

The method of claim 13 wherein said etching species comprises fluorine and said non-etching species comprises carbon-containing species.

Claim 23

Dependent Claim 11 words

The method of claim 14 wherein said interior surface comprises quartz.

Claim 24

Dependent Claim 74 words

The method of claim 9 wherein said maintaining comprises: providing a cooling element in said reactor; providing a cooling thermal path between said interior surface and said cooling element having a first heat flow rate greater than a heat flow rate from said plasma to said interior surface; and providing a heating thermal path between said interior surface and said heating element having a heat flow rate greater than said first heat flow rate.

Claim 25

Dependent Claim 37 words

The method of claim 16 wherein the step of providing a cooling thermal path comprises setting a heat flow rate of said cooling thermal path by placing a first thermally resistant element in said cooling thermal path.

Claim 26

Dependent Claim 14 words

The method of claim 17 wherein said first thermally resistant element comprises polyamide material.

Claim 27

Dependent Claim 38 words

The method of claim 17 wherein the step of providing a heating thermal path comprises setting a heat flow rate of said heating thermal path by placing an other second thermally resistant element in said heating thermal path.

Claim 28

Dependent Claim 16 words

The method of claim 19 wherein said other thermally resistant element comprises a thin air gap.

Claim 29

Dependent Claim 36 words

The method of claim 21 wherein said maintaining comprises maintaining a temperature of said interior surface at a temperature corresponding to a desired content ratio of said non-etching species and said etching species in said plasma.

Claim 30

Dependent Claim 23 words

The method of claim 21 wherein said interior surface comprises a window through which said RF power is inductively coupled into said reactor.

Claim 31

Dependent Claim 12 words

The method of claim 21 wherein said interior surface comprises crystalline silicon.

Claim 32

Dependent Claim 11 words

The method of claim 21 wherein said interior surface comprises quartz.

Claim 33

Dependent Claim 23 words

The method of claim 21 wherein said maintaining comprises maintaining said temperature in a range from about 170° C. to about 230° C.

Claim 34

Dependent Claim 23 words

The method of claim 21 wherein said maintaining comprises maintaining said temperature in a range from about 200° C. to about 300° C.

Claim 35

Dependent Claim 24 words

The method of claim 21 wherein said maintaining comprises transferring heat to said interior surface, said heat being derived from an outside heat source.

Claim 36

Dependent Claim 24 words

The method of claim 21 wherein said maintaining comprises transferring cooling to said interior surface, said cooling being derived from an outside cooling source.

Claim 37

Dependent Claim 29 words

The method of claim 21 wherein said maintaining comprises transferring cooling an heat to said interior surface, said cooling and heat being derived from outside cooling and heat sources.

Claim 38

Dependent Claim 43 words

The method of claim 21 wherein said maintaining step comprises: providing a heating element near said reactor; and applying sufficient power to said heating element so as to maintain the temperature of said interior surface above said threshold temperature by a predetermined difference.

Claim 39

Dependent Claim 32 words

The method of claim 30 wherein said sufficient power is a function of a difference between a temperature measured on a portion of said reactor and a temperature predetermined for that portion.

Claim 40

Dependent Claim 15 words

The method of claim 31 wherein said portion is an outer surface of said reactor.

Claim 41

Dependent Claim 40 words

The method of claim 22 wherein said desired content ratio in said plasma corresponds to a content ratio of said non-etching species in said polymer at which said polymer is impervious to attack by said etching species in said plasma.

Claim 42

Dependent Claim 19 words

The method of claim 33 wherein said etching species comprises fluorine and said non-etching species comprises carbon containing species.

Claim 43

Dependent Claim 74 words

The method of claim 30 wherein said maintaining comprises: providing a cooling element in said reactor; providing a cooling thermal path between said interior surface and said cooling element having a first heat flow rate greater than a heat flow rate from said plasma to said interior surface; and providing a heating thermal path between said interior surface and said heating element having a heat flow rate greater than said first heat flow rate.

Claim 44

Dependent Claim 37 words

The method of claim 35 wherein the step of providing a cooling thermal path comprises setting a heat flow rate of said cooling thermal path by placing a first thermally resistant element in said cooling thermal path.

Claim 45

Dependent Claim 14 words

The method of claim 36 wherein said first thermally resistant element comprises polyamide material.

Claim 46

Dependent Claim 38 words

The method of claim 36 wherein the step of providing a heating thermal path comprises setting a heat flow rate of said heating thermal path by placing an other second thermally resistant element in said heating thermal path.

Claim 47

Dependent Claim 16 words

The method of claim 38 wherein said other thermally resistant element comprises a thin air gap.

Claim 48

Independent Claim 110 words

A method of operating a plasma reactor having a vacuum chamber with an interior wall, comprising: introducing a fluorine-carbon containing gas into said reactor which disassociates as a plasma into an etch species which is capable of etching oxide films on a work piece in the reactor and a non-etching species combinable with the etch species into an etch-preventing polymer condensable onto said interior wall and the work piece below a characteristic deposition temperature; and maintaining a temperature of said interior wall above said characteristic deposition temperature of said etch-preventing polymer to control condensation of said polymer on said interior wall whenever said plasma is not present in the reactor.

Claim 49

Independent Claim 110 words

A method of operating a plasma reactor having a vacuum chamber with an interior wall, comprising: introducing a fluorine-carbon containing gas into said reactor which disassociates as a plasma into an etch species which is capable of etching oxide films on a work piece in the reactor and a non-etching species combinable with the etch species into an etch-preventing polymer condensable onto said interior wall and the work piece below a characteristic deposition temperature; and maintaining a temperature of said interior wall above said characteristic deposition temperature of said etch-preventing polymer to control condensation of said polymer on said interior wall whenever said plasma is not present in the reactor.

Claim 50

Independent Claim 101 words

A method of operating a plasma etch reactor, comprising: introducing a fluorine-carbon containing gas into said reactor which dissociates as a plasma into an etch species which is capable of etching oxide-containing films on a workpiece in the reactor and a non-etching species which is a precursor of a polymer condensable as an etch-preventing layer on interior wall surfaces of the reactor and surfaces of said workpiece; providing an interior surface of said reactor comprising a material which scavenges said etch species; and maintaining a temperature of said interior surface of said reactor above a threshold temperature of about 170° C.

Claim 51

Independent Claim 101 words

A method of operating a plasma etch reactor, comprising: introducing a fluorine-carbon containing gas into said reactor which dissociates as a plasma into an etch species which is capable of etching oxide-containing films on a workpiece in the reactor and a non-etching species which is a precursor of a polymer condensable as an etch-preventing layer on interior wall surfaces of the reactor and surfaces of said workpiece; providing an interior surface of said reactor comprising a material which scavenges said etch species; and maintaining a temperature of said interior surface of said reactor above a threshold temperature of about 170° C.

Claim 52

Independent Claim 87 words

A method of operating a plasma etch reactor, comprising: inductively coupling RF power into said reactor; introducing a fluorine-carbon containing gas into said reactor which dissociates as a plasma into an etch species which is capable of etching oxide-containing films on a workpiece in the reactor and a non-etching species which is a precursor of a polymer condensable as an etch-preventing layer on surfaces of the reactor and surfaces of said workpiece; and maintaining a temperature of an interior surface of said reactor above about 170° C.

Claim 53

Independent Claim 87 words

A method of operating a plasma etch reactor, comprising: inductively coupling RF power into said reactor; introducing a fluorine-carbon containing gas into said reactor which dissociates as a plasma into an etch species which is capable of etching oxide-containing films on a workpiece in the reactor and a non-etching species which is a precursor of a polymer condensable as an etch-preventing layer on surfaces of the reactor and surfaces of said workpiece; and maintaining a temperature of an interior surface of said reactor above about 170° C.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-06-22	2001-12-22	2002-06-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-06-22	2005-12-22	2006-06-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-06-22	2009-12-22	2010-06-23	$7700.00	Window Closed / Lapsed

Plasma etch apparatus with heated scavenging surfaces

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