Etch-enhanced technique for lift-off patterning
View Patent ↗An enhanced process forming a material pattern on a substrate deposits the material anisotropically on resist material patterned to correspond to an image of the material pattern. The material is etched isotropically to remove a thickness of the material on sidewalls of the resist pattern while leaving the material on a top surface of the resist pattern and portions of the surface of the substrate. The resist pattern is removed by dissolution thereby lifting-off the material on the top surface of the resist pattern while leaving the material on the substrate surface as the material pattern. Alternately, a first material layer is deposited on the resist pattern and a second material layer is deposited and planarized. The second material layer is etched exposing the first material while leaving the second material in features of the resist pattern. The first material and the resist are removed leaving the first material pattern.
1. A process for forming a first material pattern on a surface of a substrate comprising:
depositing the first material on a resist material patterned to correspond to an image of the material pattern;
depositing a second material on the first material, thereby filling any feature depressions in the resist pattern covered by the first material;
planarizing the second material to form a planarized coating;
etching the second material to remove the planarized coating from a top surface and sidewalls of the first material, exposing a portion of the first material while leaving a thickness of the second material on the first material on the surface of the substrate;
etching the exposed portion of the first material to remove the first material from a top surface and sidewalls of the resist pattern; and
removing the resist pattern by dissolution leaving the first material with the second material on the surface of the substrate thereby forming the first material pattern.
2. The process of claim 1 , wherein a thickness of the second material on the top surface of the resist pattern is less than a thickness of the second material in cavities of the resist pattern defining features of the first material pattern.
3. The process of claim 1 , wherein the etch of the second material is tuned to substantially degrade the resist material.
4. The process of claim 3 , wherein the resist material is degraded using radiation-induced resist damage or reactive ion etching (RIE) to promote removal of the resist material.
5. The process of claim 1 , wherein the deposition of the first material is anisotropic.
6. The process of claim 1 further comprising:
depositing a resist material over an area of the substrate;
exposing the resist material to an energy source defining selected sections of the resist material as the material pattern; and
removing the selected portions of the resist material to form the image of the material pattern.
7. The process of claim 1 , wherein the second material is deposited using a spin-coating process.
8. The process of claim 1 , wherein the second material is deposited via an imprint process.