Short Course Emerging Technologies for Post 14nm Cmos

It is well recognized that new device engineering is indispensable in overcoming difficulties of advanced CMOS and realizing high performance LSIs under 10 nm regime. Here, the channel materials with high mobility and, more essentially, low effective mass, are preferable under quasi-ballistic transport expected in ultra-short channel regime. From this viewpoint, Ge and IIIV semiconductor channels such as GaAs, InP, InGaAs, InAs, GaSb etc. have received strong attention for high performance CMOS logic applications. Further, MOSFETs using these materials must be fabricated on Si substrates in order to utilize Si CMOS platform, meaning the necessity of the co-integration of III-V/Ge on Si, which is often called heterogeneous integration. In order to meet the requirements of CMOS logic devices in future technology nodes, those channels must be ultrathin body structures such as ultrathin films, fin or nano-wire structures, combined with thin equivalent oxide thickness (EOT) gate insulators and low resistance source/drain (S/D), because of the need for low voltage operation and the suppression of short channel effects. The heterogeneous integration is also expected to create novel LSIs or SoCs utilizing a variety of device families along the More-than-Moore and the Beyond-CMOS direction, like opto-electronic integration and the tunneling FETs. Many technological issues need to be solved for realizing Ge/III-V MOSFETs on Si substrates. The critical issues for realizing III-V/Ge MOSFETs on the Si platform are listed as follows; (1) high quality Ge/III-V film formation on Si substrates (2) gate insulator formation with superior MOS/MIS interface quality (3) low resistivity source/ drain (S/D) formation (4) total CMOS integration. This tutorial will give the current status and future prospects of the high mobility channel MOSFET technologies for future integrated logic circuits with emphasis on the fundamental aspects of these semiconductor materials. Possible and viable technological solutions for the above critical issues will also be addressed.