Applications of High-Pressure Technology to Ulsi Fabrication

Abstract

AbstractA discourse is presented on the diverse manners and extent to which high-pressure reactors are being utilized in the semiconductor industry and their potential employment in research and development for ULSI fabrication. Various versions of high-pressure reactors are described. The major advantages of high-pressure techniques stem mainly from the ability to use lower processing temperatures which leads to reduced impurity diffusion, less wafer warpaqe, and fewer substrate defects. The exploitation of these benefits in LOCOS and FIPOS technologies for silicon IC device isolation is demonstrated. High-pressure steam has also been used to induce low-temperature reflow of PSG and BPSG before metallization. The applications and limitations of this technology are critically reviewed. Other application areas of high-pressure technigues being investigated extensively by R&D workers are discussed. These include the formation of reliable thin dielectrics in high-pressure ambients of oxygen, steam, nitrogen and ammonia, as well as the improvement of device reliability by using high pressure forming gas (H2/N2) in post-metallization annealing of radiation damage. Enhanced capabilities required for a conventional high-pressure reactor to achieve these applications are discussed. The review is complemented with data which reveal a rapidly growing utilization of high-pressure reactors for production as well as a steady growth in the number of potential applications for high-pressure techniques.