An evaluation of super-steep-retrograde channel doping for deep-submicron MOSFET applications

Formation of Ultra-Shallow Junctions

“…As with DIBL, punchthrough reduces that level of gate control over the drain current (I d ) and therefore acts as a detriment to device switching (Tian et al, 1994). As one consequence, DIBL and punchthrough both contribute to subthreshold leakage currents that lead to increased off-state power consumption.…”

Silicon MOSFETs for ULSI: Scaling CMOS to Nanoscale

“…It is also apparent that scaling down also requires higher channel doping concentration (N A ) to reduce the depletion width in addition to implementing ultra-shallow junction depth, thereby preventing the drain field from penetrating inside the channel. Channel engineering techniques (Taur et al, 1998;Tian et al, 1994) such as halo doping, super-steep retrograde well profiles along with S/D engineering techniques (Thompson et al, 1998b) such as moderately or lightly doped S/D extensions were able to extend the bulk-Si technology. A thinner physical gate-oxide thickness means that gate-leakage current increases exponentially, and maintaining gate-oxide integrity along with acceptable EI becomes a challenge.…”

Low frequency noise in advanced CMOS/SOI nanoscale multi-gate devices and noise models for applications in electronic circuits

“… Replacement of metal gate with polycrystalline Si [13]  Use of high-κ materials instead of SiO2 as gate insulators [14]  Gate stacks consisting of more than two material layers  Insertion of Halo implants near the drain and source contacts [15]  Change of doping profile [16]: increased doping with length decrease  Substrate rotation, strain, stress [17] - [18]  Shallow trench isolation (STI) [19] The well intended efforts for keeping up the high performance of standard micro-scale devices cross-cut some physical obstacles that cannot be dealt with, in a conventional way. First of all, silicon as a material has a specific bandgap that cannot be changed to fit the low voltage supply demands.…”