A surface cleaning system removes photoresist and residues from a wafer following each step of etch, film deposition or diffusion processing in preparation for the next processing step. Major methods for stripping photoresist include wet chemistries and dry or plasma technologies. Wet chemical stripping removes photoresist by immersion or spray techniques utilizing acid or solvent based liquids. Plasma based dry strip systems expose the wafer to reactive gaseous species to remove the remaining resist or residues.
The demand for surface cleaning equipment has grown as the number of required strip steps has increased. The increase in strip steps in the IC manufacturing process has led to a need for semiconductor manufacturers to increase their photoresist strip capacity and to place greater emphasis on low-damage and residue-free photoresist stripping.
Fabrication of integrated circuits with feature sizes under 90 nanometer requires advanced dry strip technologies such as our Suprema and Alpine Strip systems. In addition, faster IC devices require the use of advanced materials, such as low and ultra-low capacitance, or Low-k/ULK dielectrics, copper, metal gates, and silicides. The use of these new materials creates new challenges for photoresist stripping equipment. The resist or residues must be removed from these materials without degrading critical performance characteristics and device yield. At 32nm and below, critical ultra-shallow junctions (USJ) require cleaning processes that meet 0.3 angstroms of silicon loss per clean step according to ITRS (International Technology Roadmap for Semiconductors) specifications. Combined with the use of ULK at k values below 2.5, removing residues and preserving capacitance values requires the most advanced hardware and process capabilities.
Our strip systems enable both high productivity and advanced process development on a single product offering. We provide leading process results on a wide range of dry strip applications, including:
Strip and Residue Removal
High Dose Implant Strip (HDIS)
Bulk Resist Strip
Strip Resist over Ultra-Low-K (ULK) Films
Resist Recess Process
Resist “De-scum
Resist Strip over Metal Gates
PLAD
MLR processes
Our dry strip products encompass both 200 and 300 mm products on our Aspen platform, and our latest generation high productivity Suprema and Alpine, using our patented, inductively coupled plasma (ICP) technologies. We have a large, world-wide installed base of surface cleaning systems at 18 of the top 20 semiconductor manufacturers in high volume logic, foundry, DRAM and flash memory production facilities. With more than 1500 strip tools and 2500 ICP based plasma sources, Mattson is a partner you trust providing performance you value.
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