US6413874B1 — Method and apparatus for etching a semiconductor …

Claim 1

Independent Claim 70 words

A method for etching a semiconductor article having a surface comprising silicon, said method comprising a step of heat-treating said silicon surface in a hydrogen-containing reducing atmosphere, while keeping said silicon surface in a state disposed opposite to a surface comprising silicon oxide with a predetermined distance separating them such that said silicon surface and said surface comprising silicon oxide interact with each other to thereby etch said silicon surface.

Claim 2

Independent Claim 70 words

A method for etching a semiconductor article having a surface comprising silicon, said method comprising a step of heat-treating said silicon surface in a hydrogen-containing reducing atmosphere, while keeping said silicon surface in a state disposed opposite to a surface comprising silicon oxide with a predetermined distance separating them such that said silicon surface and said surface comprising silicon oxide interact with each other to thereby etch said silicon surface.

Claim 3

Dependent Claim 26 words

The method for etching a semiconductor article according to claim 1 , wherein said semiconductor article is an SOI substrate having a single crystal silicon film.

Claim 4

Dependent Claim 38 words

The method for etching a semiconductor article according to claim 1 or 2 , wherein said silicon surface has a root mean square of surface roughness of not smaller than 0.2 nm in a 1 μm square area.

Claim 5

Dependent Claim 22 words

The method for etching a semiconductor article according to claim 1 or 2 , wherein said silicon surface is an unpolished surface.

Claim 6

Dependent Claim 28 words

The method for etching a semiconductor article according to claim 1 or 2 , wherein said silicon surface has a surface roughness attributable to a porous silicon layer.

Claim 7

Dependent Claim 25 words

The method for etching a semiconductor article according to claim 1 or 2 , wherein said silicon surface has a surface roughness attributable to microcavities.

Claim 8

Dependent Claim 76 words

The method for etching a semiconductor article according to claim 2 , wherein said SOI substrate having a single crystal silicon film is obtained by bonding a first silicon article containing said single crystal silicon film and a separation layer for predefining a separating position to a second article and then separating the bonded assembly at the separation layer predefining the separating position so as to transfer said single crystal silicon film onto said second article.

Claim 9

Dependent Claim 26 words

The method for etching a semiconductor article according to claim 7 , wherein said separation layer is a layer implanted with inert gas or hydrogen ions.

Claim 10

Dependent Claim 20 words

The method for etching a semiconductor article according to claim 7 , wherein said separation layer is a porous layer.

Claim 11

Dependent Claim 32 words

The method for etching a semiconductor article according to claim 2 , wherein said SOI substrate has a buried oxide layer obtained by implanting oxygen ions into and heat-treating a silicon wafer.

Claim 12

Dependent Claim 57 words

The method for etching a semiconductor article according to claim 1 , wherein a flow rate of gas running near and in parallel with said silicon surface is made lower than a flow rate of gas running perpendicularly relative to and outside a surface of a peripheral area of the semiconductor article while etching said silicon surface.

Claim 13

Dependent Claim 33 words

The method for etching a semiconductor article according to claim 11 , wherein the flow rate of gas running near and in parallel with said silicon surface is made practically equal to 0.

Claim 14

Dependent Claim 54 words

The method for etching a semiconductor article according to claim 1 , wherein a silicon wafer having a silicon oxide film on its surface is arranged opposite to the silicon surface of said semiconductor article and said semiconductor article is heat-treated until the silicon oxide film is etched to expose the underlying silicon wafer.

Claim 15

Dependent Claim 30 words

The method for etching a semiconductor article according to claim 1 , wherein a tray made of silicon oxide is arranged opposite to the silicon surface of said semiconductor article.

Claim 16

Dependent Claim 26 words

The method for etching a semiconductor article according to claim 1 , wherein said hydrogen-containing reducing atmosphere contains 100% hydrogen or hydrogen and an inert gas.

Claim 17

Dependent Claim 26 words

The method for etching a semiconductor article according to claim 1 , wherein said hydrogen-containing reducing atmosphere shows a dew point not higher than −92° C.

Claim 18

Dependent Claim 32 words

The method for etching a semiconductor article according to claim 1 , wherein said semiconductor article is supported by a member containing silicon oxide at least on its surface as principal ingredient.

Claim 19

Dependent Claim 38 words

The method for etching a semiconductor article according to claim 1 , wherein said semiconductor article is arranged so as to make said silicon surface disposed perpendicularly relative to a principal flow of hydrogen-containing gas in a container.

Claim 20

Dependent Claim 72 words

The method for etching a semiconductor article according to claim 1 , wherein a plurality of semiconductor articles, each having said silicon surface, are arranged coaxially in parallel with each other at predetermined regular intervals and heat-treated in a container, while causing a hydrogen-containing gas to flow around the semiconductor articles so as to make a flow rate of gas running near and in parallel with said surface practically equal to 0.

Claim 21

Dependent Claim 34 words

The method for etching a semiconductor article according to claim 1 , wherein a quartz plate is arranged opposite to said silicon surface with a hydrogen-containing gas interposed therebetween for heat-treating said semiconductor article.

Claim 22

Dependent Claim 40 words

The method for etching a semiconductor article according to claim 1 , wherein said surface comprising silicon oxide is a rear surface of another semiconductor article, said rear surface of another semiconductor article being arranged opposite to said silicon surface.

Claim 23

Dependent Claim 28 words

The method for etching a semiconductor article according to claim 1 , wherein said article is arranged in a container having an inner wall surface comprising silicon oxide.

Claim 24

Dependent Claim 52 words

The method for etching a semiconductor article according to claim 1 , wherein a plurality of semiconductor articles are supported by a support member having a surface comprising silicon oxide so as to be arranged in parallel with each other in a container having an inner wall surface also comprising silicon oxide.

Claim 25

Dependent Claim 27 words

The method for etching a semiconductor article according to claim 1 , wherein about 10 nm to 200 nm of said silicon surface is removed by etching.

Claim 26

Dependent Claim 28 words

The method for etching a semiconductor article according to claim 1 , wherein a rate of etching said silicon surface is between 1.0×10 −3 nm/min and 1.0 nm/min.

Claim 27

Independent Claim 47 words

The method for etching a semiconductor article according to any of claims 1 , 23 , 24 or 25 , wherein a root mean square of surface roughness of said silicon surface is made to be not greater than 0.4 nm in a 1 μm square area.

Claim 28

Independent Claim 43 words

The method for etching a semiconductor article according to any of claims 1 , 23 , 24 or 25 , wherein said surface comprising silicon oxide has a thickness not smaller than 2.2 times a height to be etched from said silicon surface.

Claim 29

Independent Claim 76 words

The method for etching a semiconductor article according to any of claims 1 , 19 or 23 , wherein a plurality of semiconductor articles, each having said silicon surface, are arranged coaxially in parallel with each other at predetermined regular intervals to face a same direction and a dummy substrate or a quartz wafer substrate having a silicon oxide film on the surface is arranged foremost to face the silicon surface of the leading semiconductor article.

Claim 30

Dependent Claim 26 words

The method for etching a semiconductor article according to claim 2 , wherein said single crystal silicon film is an SOI layer formed by epitaxial growth.

Claim 31

Dependent Claim 30 words

The method for etching a semiconductor article according to claim 2 , wherein said single crystal silicon film has a film thickness between 50 nm and 500 nm before etching.

Claim 32

Dependent Claim 65 words

The method for etching a semiconductor article according to claim 1 , wherein a counter-surface constituting member comprising a silicon oxide film formed on the surface of a supporting material is arranged opposite to said article so as to allow said heat treatment to continue for a period of time sufficient to etch the silicon oxide film to expose the surface of the supporting material.

Claim 33

Dependent Claim 30 words

The method for etching a semiconductor article according to claim 2 , wherein the single crystal silicon film has a film thickness between 20 nm and 250 nm after etching.

Claim 34

Dependent Claim 44 words

The method for etching a semiconductor article according to claim 2 , wherein the single crystal silicon film has a film thickness in a range between 50 nm and 500 nm and is etched to a film thickness between 20 nm and 250 nm.

Claim 35

Independent Claim 120 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article containing therein a silicon film and a separation layer defining a separating position to a second article; separating the bonded first and second articles along the layer defining said separating position to transfer said silicon film onto said second article; and etching the surface of said silicon film transferred onto said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film such that said surface of silicon oxide and said silicon film interact with each other to thereby etch the surface of said silicon film.

Claim 36

Independent Claim 120 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article containing therein a silicon film and a separation layer defining a separating position to a second article; separating the bonded first and second articles along the layer defining said separating position to transfer said silicon film onto said second article; and etching the surface of said silicon film transferred onto said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film such that said surface of silicon oxide and said silicon film interact with each other to thereby etch the surface of said silicon film.

Claim 37

Independent Claim 110 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article comprising silicon and a second article; removing part of said first article from said bonded first and second articles so as to leave a silicon film on said second article; and etching the surface of said silicon film left on said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film such that said surface of silicon oxide and said silicon film interact with each other to thereby etch the surface of said silicon film.

Claim 38

Independent Claim 110 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article comprising silicon and a second article; removing part of said first article from said bonded first and second articles so as to leave a silicon film on said second article; and etching the surface of said silicon film left on said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film such that said surface of silicon oxide and said silicon film interact with each other to thereby etch the surface of said silicon film.

Claim 39

Dependent Claim 59 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , further comprising a step of forming a silicon oxide film on a rear surface of said second article to provide a surface of silicon oxide to be in a position opposite to a silicon film of another article to be processed.

Claim 40

Dependent Claim 38 words

The method of preparing a semiconductor article having a silicon film according to claim 35 , further comprising a step of preparing the first article by forming a non-porous single crystal silicon film on a porous silicon layer.

Claim 41

Dependent Claim 45 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , wherein said separation layer is a porous layer and said etching step is conducted after selectively etching a residual porous layer remaining on said silicon film after the separation.

Claim 42

Dependent Claim 43 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , wherein said separation layer is a porous layer and said etching step is conducted with a residual porous layer remaining on said silicon film after the separation.

Claim 43

Dependent Claim 48 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , wherein said separation layer is a layer implanted with inert gas or hydrogen ions and said etching step is conducted without polishing the surface of said silicon film exposed after the separation.

Claim 44

Dependent Claim 41 words

The method of preparing a semiconductor article having a silicon film according to claim 35 , wherein said first article comprises a porous layer and said removing step includes a step of removing the porous layer remaining on said silicon film.

Claim 45

Dependent Claim 29 words

The method of preparing a semiconductor article having a silicon film according to claim 35 , wherein a porous layer remains on said silicon film after the removing step.

Claim 46

Dependent Claim 34 words

The method of preparing a semiconductor article having a silicon film according to claim 35 , wherein the surface of said silicon film is a surface subjected to plasma etching after said removing step.

Claim 47

Dependent Claim 43 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said silicon film surface has a root mean square of surface roughness of not smaller than 0.2 nm in a 1 μm square area.

Claim 48

Dependent Claim 33 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said silicon film surface has a surface roughness attributable to a porous silicon layer.

Claim 49

Dependent Claim 30 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said silicon film surface has a surface roughness attributable to microcavities.

Claim 50

Dependent Claim 30 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , wherein said separation layer is a layer implanted with inert gas or hydrogen ions.

Claim 51

Dependent Claim 24 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , wherein said separation layer is a porous layer.

Claim 52

Dependent Claim 63 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a flow rate of gas running near and in parallel with said silicon film surface is made lower than a flow rate of gas running perpendicularly relative to and outside a surface of a peripheral area of the semiconductor article in said etching step.

Claim 53

Dependent Claim 38 words

The method of preparing a semiconductor article having a silicon film according to claim 49 , wherein the flow rate of gas running near and in parallel with said silicon film surface is made practically equal to 0.

Claim 54

Dependent Claim 60 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a silicon wafer having a silicon oxide film on its surface is arranged opposite to the silicon film of said semiconductor article and said semiconductor article is heat-treated until the silicon oxide film is etched to expose the underlying silicon wafer.

Claim 55

Dependent Claim 36 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a tray made of silicon oxide is arranged opposite to the silicon film of said semiconductor article.

Claim 56

Dependent Claim 32 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said hydrogen-containing reducing atmosphere contains 100% hydrogen or hydrogen and an inert gas.

Claim 57

Dependent Claim 32 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said hydrogen-containing reducing atmosphere shows a dew point not higher than −92° C.

Claim 58

Dependent Claim 38 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said semiconductor article is supported by a member containing silicon oxide at least on its surface as principal ingredient.

Claim 59

Dependent Claim 45 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said semiconductor article is arranged so as to make said silicon film surface disposed perpendicularly relative to a principal flow of hydrogen-containing gas in a container.

Claim 60

Dependent Claim 81 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a plurality of semiconductor articles, each having said silicon film surface, are arranged coaxially in parallel with each other at predetermined regular intervals and heat-treated in a container, while causing a hydrogen-containing gas to flow around the semiconductor articles so as to make a flow rate of gas running near and in parallel with said silicon film surfaces practically equal to 0.

Claim 61

Dependent Claim 41 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a quartz plate is arranged opposite to said silicon film surface with a hydrogen-containing gas interposed therebetween for heat-treating said semiconductor article.

Claim 62

Dependent Claim 46 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said silicon oxide surface is a rear surface of another semiconductor article, said rear surface of another semiconductor article being arranged opposite to said silicon film surface.

Claim 63

Dependent Claim 34 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said article is arranged in a container having an inner wall surface comprising silicon oxide.

Claim 64

Dependent Claim 58 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a plurality of semiconductor articles are supported by a support member having a surface comprising silicon oxide so as to be arranged in parallel with each other in a container having an inner wall surface also comprising silicon oxide.

Claim 65

Dependent Claim 34 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein about 10 nm to 200 nm of said silicon film surface is removed by etching.

Claim 66

Dependent Claim 35 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a rate of etching said silicon film surface is between 1.0×10 −3 nm/min and 1.0 nm/min.

Claim 67

Dependent Claim 46 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a root mean square of surface roughness of said silicon film surface is made to be not greater than 0.4 nm in a 1 μm square area.

Claim 68

Dependent Claim 42 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein said surface of silicon oxide has a thickness not smaller than 2.2 times a height to be etched from said silicon film surface.

Claim 69

Dependent Claim 78 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a plurality of semiconductor articles, each having said silicon film surface, are arranged coaxially in parallel with each other at predetermined regular intervals to face a same direction and a dummy substrate or a quartz wafer substrate having a silicon oxide film on the surface is arranged foremost to face the silicon film surface of the leading semiconductor article.

Claim 70

Dependent Claim 33 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the silicon film surface has a single crystal silicon film formed by epitaxial growth.

Claim 71

Dependent Claim 41 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the silicon film surface has a single crystal silicon film having a film thickness between 50 nm and 500 nm before etching.

Claim 72

Dependent Claim 41 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the silicon film surface has a single crystal silicon film having a film thickness between 20 mn and 250 nm after etching.

Claim 73

Dependent Claim 55 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the silicon film surface has a single crystal silicon film having a film thickness in a range between 50 nm and 500 nm and is etched to a film thickness between 20 nm and 250 nm.

Claim 74

Dependent Claim 32 words

The method for etching a semiconductor article according to claim 1 , wherein the temperature of said heat treatment is higher than 300° C. and lower than the melting point of silicon.

Claim 75

Dependent Claim 32 words

The method for etching a semiconductor article according to claim 1 , wherein the temperature of said heat treatment is higher than 800° C. and lower than the melting point of silicon.

Claim 76

Dependent Claim 38 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the temperature of said heat treatment is higher than 300° C. and lower than the melting point of silicon.

Claim 77

Dependent Claim 38 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein the temperature of said heat treatment is higher than 800° C. and lower than the melting point of silicon.

Claim 78

Dependent Claim 46 words

The method for etching a semiconductor article according to claim 1 , wherein a flow rate of gas flowing along an outer peripheral area of said semiconductor article in a furnace is not smaller than 10 cc/min.cm 2 and not greater than 300 cc/min.cm 2 .

Claim 79

Dependent Claim 53 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a flow rate of gas flowing along an outer peripheral area of said silicon film surface in a furnace is not smaller than 10 cc/min.cm 2 and not greater than 300 cc/min.cm 2 .

Claim 80

Dependent Claim 22 words

The method for etching a semiconductor article according to claim 1 , wherein said predetermined distance is not greater than 20 mm.

Claim 81

Dependent Claim 22 words

The method for etching a semiconductor article according to claim 1 , wherein said predetermined distance is not greater than 10 mm.

Claim 82

Dependent Claim 37 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a distance between said silicon film and said surface of silicon oxide is not greater than 20 mm.

Claim 83

Dependent Claim 37 words

The method of preparing a semiconductor article having a silicon film according to claim 34 or 35 , wherein a distance between said silicon film and said surface of silicon oxide is not greater than 10 mm.

Claim 84

Independent Claim 104 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article containing therein a silicon film and a separation layer defining a separating position to a second article; separating the bonded first and second articles along the layer defining said separating position to transfer said silicon film onto said second article; and etching the surface of said silicon film transferred onto said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film with a distance not greater than 20 mm.

Claim 85

Independent Claim 104 words

A method of preparing a semiconductor article having a silicon film, said method comprising the steps of: bonding a first article containing therein a silicon film and a separation layer defining a separating position to a second article; separating the bonded first and second articles along the layer defining said separating position to transfer said silicon film onto said second article; and etching the surface of said silicon film transferred onto said second article by heat-treating said second article in a hydrogen-containing reducing atmosphere, while arranging a surface of silicon oxide opposite to said silicon film with a distance not greater than 20 mm.

Claim 86

Dependent Claim 44 words

The method of preparing a semiconductor article having a silicon film according to claim 34 , further comprising a step of preparing the first article by forming a non-porous single crystal silicon film on a porous silicon layer which serves as the separation layer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2005-07-01	2005-12-31	2006-07-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2009-07-01	2009-12-31	2010-07-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2013-07-01	2013-12-31	2014-07-02	$7700.00	Window Closed / Lapsed

Method and apparatus for etching a semiconductor article and method of preparing a semiconductor article by using the same

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