Tuesday night was the SEMI awards banquet at ISS in Half Moon Bay. The SEMI Award was established in 1979 to recognize outstanding technical achievement and meritorious contribution in the areas of Semiconductor Materials, Wafer Fabrication, Assembly and Packaging, Process Control, Test and Inspection, Robotics and Automation, Quality Enhancement, and Process Integration.
Brewer Science and Advanced Semiconductor Engineering, Inc. (ASE), are recipients of the 2014 SEMI Award for North America. The awards honor Terry Brewer of Brewer Science for revolutionizing optical lithography with anti-reflective coatings; and Jason Chang and Tien Wu of ASE for relentlessly pursuing the commercialization of copper wire bonds when gold was the industry standard. The honorees accepted their awards during the banquet.
Some innovations become such an integral part of the semiconductor manufacturing industry’s infrastructure that the technology itself becomes fundamental — such as the use of anti-reflective coatings in optical lithography and copper for wire bonding.
Currently, multi-layer systems are commonly used in optical lithography, with some processes using 5-6 layers, as well as double- or triple-patterning steps, to achieve the necessary resolution. However, in the early 1980s, 1µm was considered the limit for optical lithography and single-layer photoresist suffered from reflections that caused significant variations in critical dimensions. Dr. Terry Brewer invented an anti-reflective coating that was effective in eliminating reflective interference and provided good adhesion to multiple materials and resist. At the time, the introduction of an anti-reflective coating was a radically different approach — adding layers to the single-layer exposure films of lithography. Brewer Science, Inc., founded in 1981, developed and commercialized anti-reflective coating materials that were instrumental in the industry’s progress from g-line to 248nm to 193nm lithography, and now to extreme ultraviolet (EUV) and directed self-assembly (DSA) technology.
Due the expense of gold for wire bonding, the semiconductor industry began exploring alternatives in the 1980s. Yet manufacturers did not adopt copper wire bonds due to concerns about yield, reliability, throughput, and customer acceptance. In 2006, Jason Chang and Tien Wu of ASE committed to underwrite risk, resolve technical problems, and address customer concerns. Requiring an investment reaching hundreds of millions of dollars with no assurance of success, in 2007 they started working with materials and equipment vendors to establish a supply chain and also with foundries to establish metallurgy for bonding pads compatible with copper wire bonds.
In 2009, Chang and Wu had dramatic results with a few selected customers. By 2013, more than half of ASE production was in copper wire bonds and today it exceeds 70 percent. ASE moved copper wire bonds into volume production and the industry benefits. Today, long-term reliability of copper wire bonds exceeds that of gold.