Abstract: BF.sub.3 based mixtures for selectively etching thin layers of silicon dioxide over silicon for use in the plasma etch process for integrated circuits manufacture is disclosed.In the process, when trace amounts of formaldehyde are added to the etch system the rate on oxide inceases markedly. The effect on the silicon is not substantial. The optional addition of an inert diluent gas did not substantially change these results.

Abstract: A single step method for boron dopant diffusion implementing both deposition and drive-in diffusions in one furnace process is provided. By using a spin-on dopant in a diffusion furnace with pyrogenic steam and thermal ramping capabilities, sheet resistivities and penetrations to a precision and accuracy of 4% with one furnace step are achievable. The one step method disclosed circumvents the use of two furnace processes to achieve a typical p-type diffusion which requires a deposition in a furnace set at one temperature followed by a drive in diffusion in a furnace set at a second temperature after deglazing in a hydrofluoric acid. Also attainable by the one step process disclosed are resistivity uniformities better than those with the two furnace processes.

Abstract: A boron doped, silicon oxide-forming film is produced on a semiconductor wafer by coating the wafer with a solution of a silicon compound and a boron compound, in a blend of two polar organic solvents, one of which has a low boiling point, and the other has a high boiling point, between 185.degree. and 300.degree. C. During a subsequent heating step, the high boiling point solvent redissolves any crystalline precipitate that forms during spin-on, giving a more uniform film for diffusion, and consequently a damage-free wafer surface.