SCORR - supercritical carbon dioxide resist removal.
- Gunilla B.
- Laurie L.
- William K.
- Craig M.
SCORR, short for supercritical carbon dioxide resist removal, is a new technology that could continue to enable the technological development of photolithography processes in industry. SCORR is based upon the physical properties of supercritical fluids (SCFs). These special properties enable SCFs to remove coatings, residues, and particles froin high-aspect-ratio structures in integrated circuits (ICs). SCORR also eliminates rinsing and drying steps presently used in IC manufacture, thereby eliminating the generation of millions of gallons of water per fab per day. Fabricating integrated circuits relies heavily on photolithography to define the shape and pattern of individual components. Once a single stage of a silicon wafer's topography has been completed, the hardened resist must be removed. Conventional processes generates more waste than any single step in the IC manufacturing process, and the production of a complete IC can involve many photolithography iterations. The cost associated with the treatment and disposal of this waste, as well as employee health and safety considerations, are driving a search for a1 ternative, environmentally benign, cost-effective solutions. In addition, photoresist stripping is confronting finer architectures and higher aspect ratios, as well as new low-k materials that are highly sensitive to post-etch residue. Low-k dielectrics and low-resistivity conductors such as copper are necessary for meeting industry's need for faster and smaller chips. Further, each low-k choice requires different plasma-etching processes, or chemistries, to etch structures into the low-k material; therefore, the nature of the residues can be different. No one product can meet all copper/low-k applications, and existing chemistries are not tunable - or even desirable - for the new processes. We have developed a new process - known as SCORR - that removes photoresist and post-ash, -etch, and -CMP (particulate) residue from semiconductor wafers. As IC feature sizes become smaller, the need for ensuring particle removal will increase. With feature sizes of less than 0.18{micro}m, it will become imperative that all particles greater than about 0.1 micron be removed from the semiconductor wafer. Existing cleaning technologies (such as liquid or high-pressure jet scrubbing) cannot remove particles on the order of 0.1 micron because of surface boundary layer constraints. Because of the low viscosities of supercritical fluids (SCFs), these constraints are virtually eliminated.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 974696
- Report Number(s):
- LA-UR-02-0784; LA-UR-02-784; TRN: US201007%%951
- Resource Relation:
- Conference: Submitted to: 3rd International Conference on Mocroelectronics and Interfaces, Santa Clara, CA, Feb. 12-14, 2002.
- Country of Publication:
- United States
- Language:
- English
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