Abstract:
An n type impurity region is provided below a gate electrode. By setting a gate length to be less than a depth of a channel region, a side surface of the channel region and a side surface of the n type impurity region adjacent to the channel region form a substantially perpendicular junction surface. Thus, since a depletion layer widens uniformly in a depth direction of a substrate, it is possible to secure a predetermined breakdown voltage. Furthermore, since an interval between the channel regions, above which the gate electrode is disposed, is uniform from its surface to its bottom, it is possible to increase an impurity concentration of the n type impurity region, resulting in an achievement of a low on-resistance.
Abstract:
In a MOSFET, after an element region is formed, a wiring layer is formed subsequently to a barrier metal layer, and hydrogen annealing is performed. However, in the case of an n-channel MOSFET, a threshold voltage is lowered due to an occlusion characteristic of the barrier metal layer. Thus, an increased impurity concentration in a channel layer causes a problem that reduction in an on-resistance is inhibited. According to the present invention, after a barrier metal layer is formed, an opening is provided in the barrier metal layer on an interlayer insulating film, and hydrogen annealing treatment is performed after a wiring layer is formed. Thus, an amount of hydrogen which reaches a substrate is further increased, and lowering of a threshold voltage is suppressed. Moreover, since an impurity concentration in a channel layer can be lowered, an on-resistance is reduced.
Abstract:
A novel fluorine-containing polymeric compound represented by the general formula--CH.sub.2 --CH[(CH.sub.2).sub.a --NH.sub.2 ]}.sub.m-n--CH.sub.2 --CH[(CH.sub.2).sub.a --NH--CO--NH--CH.sub.2).sub.a Rf]}.sub.n,in which Rf is a perfluoroalkyl group having 6 to 15 carbon atoms, m is a positive integer in the range from 10 to 1500, n is a positive integer smaller than 0.7 m and a is 0 or 1, is prepared by the reaction of, when a is 0, a polyvinylamine of the formula --CH.sub.2 --CHNH.sub.2 ].sub.m, with an alkyl perfluoroalkanoate of the formula Rf--CO--OR, in which R is an alkyl group having 1 to 5 carbon atoms, or, when a is 1, a polyallylamine of the formula --CH.sub.2 --CH(CH.sub.2 --NH.sub.2)].sub.m, with a perfluoroalkylmethyl isocyanate of the formula RfCH.sub.2 --NCO. Despite the high fluorine content, the polymer is soluble in at least one kind of organic solvents so that Langmuir-Blodgett's films can be prepared from a solution of the polymer. The LB films have an extremely low surface energy and useful as a material for protection and modification of various surfaces.