초임계 이산화탄소를 이용한 미세전자소자의 제조

Abstract

Over the last 30 years the semiconductor industry was enabled primarily through advances in equipment design and through process changes that provided scaling (ongoing reduction of feature sizes). Recently, increased numbers of new materials, integration schemes, high aspect ratio structures, and features with tighter pitch and smaller CD？fs are pushing the limits of current processing techniques and may require new solutions to meet these challenges, not simply the next generation of equipment. Wafer processing with supercritical carbon dioxide (scCO2) is an example of a novel technology, which could solve many future roadblocks on currently on the processes. Carbon dioxide is nontoxic, nonflammable, inert, and is not surprisingly the leading candidate for a more environmentally responsible replacement for organic and aqueous solvents in many processes in semiconductor industry. Numerous proposed CO2 applications that are both process enabling and potential for chemical abatement in microelectronics engineering include stripping, drying, developing, and spinning of photoresist, chemical fluid deposition of metals, etching of sacrificial oxide, and repairing of plasma damaged low k dielectrics. In this thesis, the silylating effect of TMCS, HMDS and TMDCS in scCO2 on O2 plasma ashed SiOCH low-k dielectrics was studied for the rapid restoration of hydrophobicity as well as a high-dose ion-implanted photoresist (HDIPR) was stripped off from the surface of a semiconductor wafer by using a mixture of supercritical carbon dioxide and a co-solvent. Moreover, we studied about dry etching process using supercritical carbon dioxide (scCO2). As a result, this green solvent is being considered for use to advantage etching of sacrificial layers with high selectivity toward Poly Si structural layers. Furthermore, scCO2？]based solutions in wafer etching would eliminate the water？]based drying step and prevent structural damage to materials in microelectronic devices.