Abstract: The adhesion of plastic encapsulants to electrical leadframes containing substantial amounts of copper is improved by exposing the leadframes to an active oxygen ambient (e.g., 10-30% H.sub.2 O.sub.2) at temperatures below the leadframe annealing temperature (e.g., room temperature to 100.degree. C.) for a few minutes. There is no need to remove the native oxide. A preliminary degreasing step is desirable but not essential. The treatment strengthens any native oxide present on the leadframes without producing an oxide which is so thick as to interfere with subsequent bonding of electronic components or connecting wires to the leadframe. Delamination between the leadframe and the plastic encapsulant by temperture cycling from -65.degree. to 150.degree. C. is substantially reduced.

Abstract: A process is disclosed for doping a semiconductor substrate which achieves a lower sheet resistivity than is otherwise obtainable. A spin-on dopant material is applied to the surface of the semiconductor substrate and subsequently heated to drive off solvents contained in the dopant material. The layer of spin-on dopant material is then plasma treated, preferably in an oxygen plasma, to enhance the diffusion properties of the spin-on material. The substrate and dopant material are then heated to an elevated temperature to accomplish the desired depth of diffusion.

Abstract: A method is presented for the uniform and reproducible boron doping of many closely spaced silicon wafers in a single batch, wherein a particular process sequence and specified ranges of reactant gas compositions, flow rate and pressure are utilized. The method is illustrated for BCl.sub.3 as a boron source gas and H.sub.2 and O.sub.2 as an oxidant gas. Superior results are obtained when BCl.sub.3 and H.sub.2 O are present in the reaction chamber at pressures less than 10 Torr (1.3 kPa) and molar ratios are in a specific range close to but not equal to that necessary for stoichiometric production of B.sub.2 O.sub.3.

Abstract: A protective coating composition for photoresist layers comprising an aqueous solution of a vinyl alcohol polymer, at least one surfactant having wetting properties and at least one surfactant having lubricant properties is disclosed. An improved process for forming a photoresist pattern employing this protective coating composition is also disclosed. The composition and process are particularly useful in the fabrication of semiconductor devices.

Abstract: An improved metallization system for semiconductor substrates comprising successive layers of at least one barrier metal and tin is disclosed. A semiconductor package comprising a housing of impervious material, a semiconductor device having the metallization system of this invention disposed in the housing and conductor means bonded to the tin on the semiconductor device is also disclosed. The system is of particular usefulness in double stud diode packages.

Abstract: A molding compound consisting essentially of 0.1 to 10 percent of N-methyl-2-pyrrolidone and a resin selected from the group consisting of epoxy, phenolic and silicone resins. The compound is injected in the mold as in the standard molding process and reacts with any surface contamination that may remain from the previous injection. The contamination is thereby removed with the removal of the molded device and the process is essentially self-cleaning.

Abstract: Immersion of semiconductor devices, particularly diodes, having a defective tin plating thereon in a solution of 5 - 20 percent by weight trichloroacetic acid, 0.1 to 5 percent by weight of a compound selected from the group consisting of cationic, anionic, and nonionic surfactants and the balance water effectively removes the tin therefrom. The process is effective at room temperature but preferably is performed at approximately 100.degree. C.

Abstract: A composition for the corrosion protection of a metallized semiconductor die or wafer containing an alcohol solution of boron, phosphorous and a metal selected from the group consisting of gold, palladium, rhodium and platinum. The solution is prepared by mixing phosphorous pentoxide in an alcohol solvent. The dissolution of the phosphorous pentoxide is exothermic and the temperature of the solution will rise during the reaction. Then boric anhydride and a salt or oxide of gold, palladium, rhodium or platinum are added to the solution.

Abstract: A process for preparing an aluminum foil for coating with photoresist for the purpose of preparing an etched strip for semiconductor assembly utilizing the step of cleaning said aluminum surface with a water solution comprising one to five percent ammonium persulfate, one to five percent sodium chlorate and one to three percent of a surfactant selected from the group consisting of dioctyl sodium sulfo succinate and dodecyl benzene sulfonate.

Abstract: A process for the stabilization of an aluminum part, such as a semiconductor lead frame, which includes the step of coating said aluminum part with an alcohol solution containing boron, phosphorous and a metal selected from the group consisting of gold, palladium, rhodium and platinum. The solution is prepared by mixing phosphorous pentoxide in an alcohol solvent. The dissolution of the phosphorous pentoxide is exothermic and the temperature of the solution will rise during the reaction. Then, boric anhydride and a salt of gold, palladium, rhodium or platinum is added. The solution strips any aluminum oxide from the surface of the part while also removing any organic contamination and while depositing a layer of the gold, platinum, rhodium or palladium onto the surface of the aluminum part. The process is particularly advantageous for preparing aluminum lead frames for wire bonding during semiconductor device assembly.