Abstract: The invention provides a method for forming a protective silicon carbide (SiC) film on a silicon (Si) substrate. The method permits the formation of silicon carbide on the Si substrate on all surfaces simultaneously. The process is highlighted in that the silicon substrate to be coated is placed in a susceptor having tantalum carbide surfaces and which has a high purity ambient. The substrate is heated at a temperature about 1250.degree. C to remove native SiO.sub.2 from its surface. The system is then cooled to a temperature of about 900.degree. C and methane is added for about 30 minutes to thereby deposit a layer of carbon which is further reacted with the Si substrate at 1250.degree. C to form a smooth, pin hole free SiC film. SiC layers are also formed by a one step reaction in which methane is reacted directly with Si at 1250.degree. C.

Abstract: A method for etching at least one aperture having a defined crystallographic geometry in single crystals which includes masking the crystal to protect predetermined portions thereof from being etched, and then anisotropically etching with a mixture of sulfuric acid and phosphoric acid.

Abstract: A process for controlling the softening point and for providing a preselected softening point of solder glass which comprises bubbling oxygen-containing gas through a homogeneous melt of a solder glass containing copper oxide at a temperature and oxygen partial pressure predetermined to provide the desired preselected softening point of the solder glass and for a time sufficient to achieve equilibrium of the reaction Cu.sub.2 O+1/2O.sub.2 .revreaction.2CuO.