Material Properties & Local Phenomena in High K Dielectrics

A number of "new materials" are currently under consideration to replace SiO₂ and SiO_xN_y for a key component of Si-based integrated circuit technology: the gate dielectric for the transistor. Selecting new high-k gate dielectric materials systems requires the consideration of many properties. These may be divided into two broad categories: (a) fundamental materials properties that include permittivity, barrier height, stability in direct contact with Si, and film morphology, and (b) device processing, integration and performance issues such as interface quality, gate compatibility, process compatibility, and, of course, reliability. The issues that both of these categories encompass must be simultaneously addressed for any successful, manufacturable gate dielectric solution. An in-depth review of the required materials properties, including why certain materials display the desired properties and why others do not will be presented, in addition to an overview of the impact of these materials on defect structure, transport and device performance.

Glen D. Wilk is an Executive Scientist at ASM America, in the Transistor and Capacitor Products unit. He specializes in high-k dielectrics and front-end topics, including advanced CMOS device integration. He received his B.S. in Materials Science and Engineering from Cornell University (1990), and his M.S. (1991) and Ph.D. (1995) in Applied Physics from Harvard University, with his dissertation on topics related to surface physics and surfactant-mediated epitaxial growth of Si and Ge. Dr. Wilk joined the Central Research Labs at Texas Instruments as a member of technical staff (MTS) from 1995 to 1999, where he focused on topics including Si quantum well devices and high-k gate dielectrics, and advanced devices. In 1999, Dr. Wilk joined Bell Laboratories, Lucent Technologies as an MTS in the Electronic Device Research Department. He continued his research on high-k gate dielectrics at Bell Laboratories, as well as research in the areas of optoelectronic and high-speed devices, including LiNbO3 modulators, MEMS optical cross-connects and III-V MOSFETs. In 2001, Dr. Wilk continued work in these areas while joining the Agere Systems spinoff from Lucent, where he became distinguished member of technical staff (DMTS) in 2002. He joined ASM America (see above) in 2003. Dr. Wilk has served on technical committees for IEEE IEDM and SISC conferences, as well as the AVS ALD conference, and is currently on the executive committee for the SISC conference. Dr. WIlk currently has authored or co-authored over 40 publications in peer-reviewed journals, including several review papers on high-k gate dielectrics, and holds over 20 U.S. patents, in addition to over 20 patents pending.