December 13, 2000
FRONTIERS IN MATERIALS SCIENCE
VINSE COLLOQUIUM SERIES
Dr. Martin Green
Bell Laboratories/Lucent Technologies
"Finding Alternate Gate Dielectrics to Replace SiO2 in Integrated Circuit Devices: A Classic Materials Science Case Study"
Abstract. Nature has endowed the silicon microelectronics industry with a wondrous gate dielectric material, SiO2. It is native to silicon, and with it forms a low defect density interface. It has high resistivity, excellent dielectric strength, a large band gap, and a high melting point. These properties of SiO2 are in large part responsible for enabling the microelectronics revolution. SiO2 has been the gate dielectric material of choice since the advent of the integrated circuit. In spite of its many attributes, however, SiO2 suffers from a relatively low dielectric constant. Since high gate capacitance is necessary to produce the required drive currents for submicron devices, and further since capacitance is inversely proportional to gate dielectric thickness, the SiO2 layers have of necessity been scaled to ever thinner dimensions. Soon SiO2 layers will be so thin (~1.3 nm) that excessive leakage current will compromise their performance. Alternate, higher dielectric constant gate dielectrics will be required. It is not often that a completely new material is introduced into the conservative world of silicon microelectronics. In this talk I will couch this problem in terms of the classic materials science project that it is: materials selection, processing, properties and performance.