8 July 2013
SSEC adds WaferEtch and WaferStorm platforms to single-wafer wet processing product portfolio
At the SEMICON West 2013 event in San Francisco (9-11 July), Solid State Equipment LLC (SSEC) of Horsham, PA, USA, which makes single-wafer wet processing equipment, is introducing its WaferEtch and WaferStorm product lines. These platforms are specifically configured to meet the process needs of leading-edge applications in advanced packaging, MEMS and compound semiconductor manufacturing, with an emphasis on improved process control and reduced chemistry consumption, which translates to higher throughput and lower cost of ownership (CoO).
One key CoO reduction driver was enabled by an engineering breakthrough that makes the chambers more compact and stackable. This results in 50% more process chambers within the same small footprint of the legacy products.
The WaferEtch platform is configured for aqueous-based etch processes such as through-silicon via (TSV) reveal. The WaferStorm platform is configured for solvent-based processes such as resist strip, metal lift-off, and TSV cleaning.
“Superior performance, improved yields, and increased throughput at a lower CoO are the cornerstones of SSEC's single-wafer wet processing approach,” says chief technical officer Laura Rothman Mauer. “We have worked closely with our customers to develop practical solutions to some of the industry's toughest manufacturing challenges in 2.5D and 3D ICs, MEMS, and compound semiconductors,” she adds. “The launch of these preconfigured product lines is the culmination of this work.”
The WaferEtch platform is an aqueous-based, customizable platform uniquely configured to meet the needs of specific etch applications for 3D ICs, MEMS, and compound semiconductor processes. The systems use a wet etch process chemistry that demonstrates optimal etch rate and in-situ cleaning.
The flagship of the WaferEtch platform, the TSV REVEALER, is specifically configured to address the requirements of TSV reveal (where the backside of the wafer is thinned to reveal the copper interconnects), which has become a target area in the manufacture of 2.5D and 3D IC packaging for process control and cost reduction. The TSV REVEALER replaces three tools required for the dry etch approach: plasma etch, silicon thickness measurement, and clean. An optical end-point detection system with advanced algorithms determines when vias are revealed. Integration of a wafer thickness measurement sensor in the etch system provides closed-loop control of the etching process. The TSV REVEALER achieves a significant reduction in CoO making 3D TSVs more economically feasible.
The WaferStorm platform is a solvent-based platform, initially available in three unique configurations: TSV CLEANER, METAL LIFTER, and DRY FILM REMOVER. All WaferStorm systems are based on SSEC's unique soak and spray technology, which provides improved performance at lower CoO than conventional wet bench-only or spray-only approaches. The process combines equal soak time in the wet buffer tank for each wafer, followed by spray, and then a final step depending on the process being performed. This unique combination minimizes both spray time and chemistry use, and adds a significant level of process control. The reduction in spray time results in increased throughput.
- WaferStorm TSV CLEANER - TSV clean is a critical process step that is essential to reliability. The deep reactive ion etch (DRIE) process leaves behind a polymer residue which can lead to defects and voids in the barrier, seed, and fill steps that follow. SSEC’s WaferStorm TSV CLEANER is proven to remove residues in high-aspect-ratio holes that wet bench-only or spray-only tools leave behind. The tool features equal-time soak software for process control.
- WaferStorm METAL LIFTER - Metal lift-off consists of the sequential steps of photolithography, metal deposition, and solvent lift-off of both metal and non-metal substances in MEMS and compound semiconductor applications. The SSEC WaferStorm METAL LIFTER is configured specifically to perform the sequential soak and spray combinations unique to the process. The immersion station operates in a low-oxygen atmosphere, which maintains the bath longer. Following a soak in the immersion tank, lift-off takes place in a spray station using a high-pressure chemical spray, which translates to increased throughput. The tool features a lift-off material filtration station and strainers for separating metal films, resulting in the complete removal of the metal.
- WaferStorm DRY FILM REMOVER - Removal of dry film resists used in advanced microbumping processes for 3D ICs and wafer level packaging (WLP) applications is a challenge due to the film thickness and composition. The SSEC WaferStorm DRY FILM REMOVER combines heated chemistries and proprietary soak and spray at high pressure for rapid and complete removal of stubborn dry film residue. The soak step uses heated solvents throughout the buffer cycle time. After being softened by the soak, the wafers are transferred to the single-wafer spray station where they are exposed to high-pressure fan sprays with heated solvents for rapid removal of dry film residue. This combination ensures thorough removal and increased throughput.
The new WaferEtch and WaferStorm platforms are being exhibited in booth #2023 (Moscone Center, South Hall) at SEMICON West.