Removing a low-k dielectric layer from a wafer
AssigneeApplied Materials, Inc.
InventorsHong Wang, Krishna Vepa, Paul Miller
Life of this patent
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Abstract
A low-k dielectric layer having a composition of silicon, oxygen and carbon, and optionally hydrogen, is removed from a test or production wafer to refresh the wafer. The low-k dielectric layer is removed by immersing a surface of the low-k dielectric layer in a first etching solution having a first composition that is believed to break the Si—O bonds in the dielectric layer; and immersing the surface of the low-k dielectric layer in a second etching solution having a second composition that is believed to break the Si—C bonds in the low-k dielectric layer.
Claims23
A method of removing a low-k dielectric layer from a wafer, the low-k dielectric layer (i) having a k value of less than about 3, (ii) comprising silicon, oxygen and carbon, and (iii) having Si—O and Si—C bonds, and the method comprising:
- (a) immersing a surface of the low-k dielectric layer in a first etching solution comprising at least one of HF and NH4F, whereby the first etching solution is capable of breaking the Si—O bonds in the low-k dielectric layer;
- and
- (b) immersing the surface of the low-k dielectric layer in a second etching solution comprising at least one of H2SO4 and H2O2, whereby the second etching solution is capable of breaking the Si—C bonds in the low-k dielectric layer.
A method of removing a low-k dielectric layer from a wafer, the low-k dielectric layer (i) having a k value of less than about 3, (ii) comprising silicon, oxygen, and carbon, and (iii) having Si—O and Si—C bonds, and the method comprising:
- (a) immersing a surface of the low-k dielectric layer in a first etching solution comprising at least one of HF and NH4F, whereby the first etching solution is capable of breaking the Si—O bonds in the low-k dielectric layer;
- and
- (b) immersing the surface of the low-k dielectric layer in a second etching solution comprising at least one of H2SO4 and H2O2, whereby the second etching solution is capable of breaking the Si—C bonds in the low-k dielectric layer,
- whereby the low-k dielectric layer is removed from the wafer.
A method of removing a low-k dielectric layer from a wafer, the low-k dielectric layer (i) having a k value of less than about 3, (ii) comprising silicon, oxygen, and carbon, and (iii) having Si—O and Si—C bonds, and the method comprising:
- (a) immersing a surface of the low-k dielectric layer in a first etching solution comprising HF and NH4F;
- and
- (b) immersing the surface of the low-k dielectric layer in a second etching solution comprising H2SO4 and H2O2 in a molar ratio of from about 1.4:1 to about 31:1.
Dependencies are inferred from the claim text.