Abstract:
An improvement in the method of ion implantation into a semiconductor substrate through a photoresist mask wherein the photoresist mask is subjected to an RF gas plasma oxidation prior to the ion implantation step for a period sufficient to reduce the thickness of the photoresist layer. The ion implantation is then carried out through the treated photoresist mask.
Abstract:
Non-doping ions are implanted in the electrode layer of a semiconductor to reduce contamination of the electrode layer by mobile ions. The dosage of the ions is selected to prevent an increase in the fast surface state density when the ions are implanted. The energy level at which the ions are implanted is controlled to position all of the implanted ions within the electrode layer.
Abstract:
A method for producing integrated circuit resistors of relatively high resistivity which are temperature stable, i.e., have a low temperature coefficient of resistance at operating temperatures. The resistor is formed in a selected region of an integrated circuit substrate through the introduction of appropriate dopant ions by standard ion implantation or diffusion techniques. However, the concentration of such introduced dopant ions is in excess of the concentration ordinarily required by such techniques. The region into which such dopant ions are introduced is subjected to a bombardment with non-dopant ions at a dose which is sufficient to damage the crystal structure of the region but insufficient to form an amorphous phase in this bombarded region; the bombardment may be carried out either before, after or, where appropriate, even simultaneously with the introduction of the dopant ions. As a result of this ion bombardment, the sheet resistance of the resistor region becomes substantially higher than the selected resistance despite the presence of excess dopant ions. Then, the substrate is heated at a temperature of from 500*C. to 800*C. for a time sufficient to partially anneal the damage so as to lower the sheet resistance of the region to the selected sheet resistance. The annealing time/temperature cycle is carried out so as to maintain the temperature coefficient of resistance below the temperature coefficient of resistance for conventional high resistivity resistors produced by ion implantation or diffusion.
Abstract:
Disclosed is a method of electrolessly plating an alloy onto a substrate. To plate an alloy consisting of two elements requires the steps of mixing two solutions, each containing one of the elements to be alloy plated, and immersing a surface to be plated in said mixed solution for a fixed period of time until a desired thickness of alloy has been plated onto the surface.