Suppression of cobalt silicide agglomeration using nitrogen (N/sub 2//sup +/) implantation
In this paper, the effects of nitrogen coimplantation with boron into p/sup +/-poly gate in PMOSFETs on the agglomeration effects of CoSi/sub 2/ are studied. The thermal stability of CoSi/sub 2//poly-Si stacked layers can be significantly improved by using nitrogen implantation. Samples with 40-nm cobalt silicide (CoSi/sub 2/) on 210-nm poly-Si implanted by 2/spl times/10/sup 15//cm/sup 2/ N/sub 2//sup +/ are thermally stable above 950/spl deg/C for 30 s in N/sub 2/ ambient. If the dose of nitrogen is increased up to 6/spl times/10/sup 15//cm/sup 2/, the sheet resistance of CoSi/sub 2/ film is not increased at all, and TEM photographs show that the agglomeration of CoSi/sub 2/ film is completely suppressed.
Effects of nitrogen implantation in silicon for shallow p+-n junction formation
This letter will present the effects of nitrogen implantation on shallow p+-n junction formation in silicon. The p+-n junctions fabricated at different implantation conditions and heat budgets were characterized by secondary ion mass spectroscopy, current–voltage and capacitance–voltage measurements, and analyzed by transport of ions in matter simulation. The capacitance–voltage measurements of nitrogen implanted samples revealed the one-sided abrupt junction properties, and the current–voltage measurements indicated the shallow junction characteristics due to boron diffusion suppression by nitrogen. The activation energy is about 0.39 eV for temperatures below 80 °C, and its dominant leakage mechanism is phonon-assisted tunneling. At a reverse bias of −3 V, the leakage current density was 5.217×10−8 A/cm2 at −3 V, which is comparable to that of a conventional p+-n junction.
Nonenzymatically galactosylated serum albumin in a galactosemic infant.
Galactosemia is a molecular disease of genetic origin that is characterized by a deficiency of galactose-1-phosphate uridyltransferase.1 , 2 The resulting severe impairment of galactose metabolism ...