Equipment and Manufacturability Issues in Chemical Vapor Deposition Processes

Device scaling continues to drive increasingly stringent requirements of thin films from the transistor through the interconnect layers. Such films that enable scaling include those in the high-k gate stack to minimize leakage, channel materials, and stressors for mobility enhancement, metals in the back end for low-resistance interconnects, and low-k dielectrics to minimize parasitic capacitance. Chemical vapor deposition (CVD) is routinely utilized to deposit all the aforementioned films with a quality and throughput that delivers enhanced device performance and a reduced per-transistor cost with each succeeding technology node. This chapter provides an overview of CVD equipment and the films CVD is capable of depositing in the device fabrication process. Several CVD technologies (including atmospheric, low-pressure, plasma-enhanced, and metal-organic CVD) and their applications in semiconductor manufacturing for depositing metals, dielectrics, and epitaxial semiconductors are reviewed. The goal here is to enable the reader to make an educated decision on which CVD technology to use based on application, material, and manufacturing needs. Practical matters related to CVD equipment and deposition such as metrology, contamination concerns, and equipment procurement are also covered. The chapter begins with a history of CVD and finishes with recent trends in CVD technology.