CMOS Dual-Work-Function Engineering by Using Implanted Ni-FUSI
For the first time, a simple CMOS fully silicided (FUSI) process achieving n/pMOS band-edge work function was demonstrated, which is fully compatible with conventional CMOS process. Dual-work-function CMOS FUSI, with a wide range of 800 mV, was achieved by implantation of Yb into the poly of the nMOS gate (4.1-eV work function) and Ga into the poly of the pMOS gate (4.9-eV work function), respectively. The placement of the tuning elements at the metal/dielectric interface was engineered with the thermal budget, as well as the implant dose and species.
Significant improvement of 45 nm and beyond complementary metal oxide semiconductor field effect transistor performance with fully silicided and ultimate spacer process technology
Abstract A fully silicided (FUSI) metal gate process is merged with ultimate spacer process (USP) strain engineering to effectively enhance the performances of deep nano complementary metal oxide semiconductor field effect transistor (CMOSFET). Using the merged FUSI–USP process, the FUSI gate can be processed with the source/drain region silicide in one step, and the poly gate can be thinned to less than 300 A, thus shortening the distance between the strain contact etch stop layer and the channel to generate higher stress. Therefore, Ion gain up to 28% can be achieved in an n type MOSFET with tensile-stress, and 40% in a p type MOSFET with compressive-stress.
Synthesis of 2,4-dideoxy-.beta.-D-erythro-hexopyranosyl nucleosides
The synthesis of 1-(2,4-dideoxy-β-D-erythro-hexopyranosyl)thymine (12) 1 was accomplished using two different synthetic routes. It was obtained starting either from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose or from tri-O-acetyl-D-glucal. The other modified nucleosides, with either a cytosine, guanine, or adenine moiety, were synthesized using the second reaction scheme. Deoxygenation reactions were accomplished with the (2,4-dichlorophenoxy)thiocarbonyl derivatives generated in situ