Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
168 words
In a plasma generator wafer-etching machine having an rf emitting electrode, semiconductor wafer-mounting chuck spaced from said emitting electrode forming a plasma reaction zone therebetween and wherein said emitting electrode includes a cap having multiple apertures and a gas diffusor within said cap, a top surface of said cap bounding one side of said zone and wherein said apertures are positioned to receive and convey an etching gas to said zone, the improvement comprising: means operable at a given dark dspace thickness including a predetermined RF power level and a predetermined pressure of etching gas and including having said apertures of sufficient surface area for permitting a plasma sheath resultant from plasma formed in said zone to extend into said apertures from said zone while preventing extension of the plasma sheath from said cap to said diffusor; and means for reducing sputtering of said cap by providing that said apertures are of such diameter and depth such that the plasma sheath area adjacent to the cap is maximized.
Claim 2
Dependent Claim
168 words
In a plasma generator wafer-etching machine having an rf emitting electrode, semiconductor wafer-mounting chuck spaced from said emitting electrode forming a plasma reaction zone therebetween and wherein said emitting electrode includes a cap having multiple apertures and a gas diffusor within said cap, a top surface of said cap bounding one side of said zone and wherein said apertures are positioned to receive and convey an etching gas to said zone, the improvement comprising: means operable at a given dark dspace thickness including a predetermined RF power level and a predetermined pressure of etching gas and including having said apertures of sufficient surface area for permitting a plasma sheath resultant from plasma formed in said zone to extend into said apertures from said zone while preventing extension of the plasma sheath from said cap to said diffusor; and means for reducing sputtering of said cap by providing that said apertures are of such diameter and depth such that the plasma sheath area adjacent to the cap is maximized.
Claim 3
Dependent Claim
39 words
The invention of claim 1 in which said means for reducing sputtering comprises, having each said aperture of a diameter and height sufficiently large to accommodate the plasma sheath without giving rise to local nonuniformities in wafer etch rate.
Claim 4
Dependent Claim
26 words
The invention set forth in claim 2 in which said apertures are in multiple hexagon patterns across essentially all of the top surface of said cap.
Claim 5
Dependent Claim
26 words
The invention set forth in claim 1 further comprises means spaced between said cap and said diffusor for preventing arcing between said diffusor and said cap.
Claim 6
Dependent Claim
42 words
The invention of claim 4 in which said means for preventing arcing comprises a ledge on an inner peripheral wall of said cap extending between said apertured cap and said diffusor such that a gap is formed between the cap and diffusor.
Claim 7
Dependent Claim
20 words
The invention of claim 5 in which said diffusor extends from said ledge to a bottom edge of said cap.
Claim 8
Dependent Claim
30 words
The invention of claim 1 wherein said cap has an apertured top with circular apertures having a vertical height greater than r/2 where r is the radius of the apertures.
Claim 9
Dependent Claim
46 words
The invention of claim 7 wherein the height of said apertures formed in a central portion of the cap top are less than the height of apertures formed radially of said central portion such that uniformity of etch over the surface of a wafer is obtained.
Claim 10
Dependent Claim
30 words
The invention set forth in claim 8 in which said cap top includes an apertured tapered radial portion extending from said central portion to vertical edge portions of said cap.
Claim 11
Dependent Claim
34 words
The invention set forth in claim 1 in which the ratio of the total area of said apertures to the area of the cap bounding said zone is from about 2 to about 6.
Claim 12
Dependent Claim
17 words
The invention set forth in claim 4 in which said diffusor is spaced from said cap apertures.