Abstract: The device and method for performing an optical Hall test provide means for on-destructive measurement of free carrier concentration or effective mass in semiconductor materials using Faraday rotation spectra. A beam emitted by a Fourier transform infrared (FTIR) spectrometer is transmitted through the sample that is mounted between a polarizer and analyzer and the opposite poles of a magnet before finally being incident on a detector. The ratio of the samples's transmission spectrum with the magnetic field on to that with the magnetic field off is converted, through a suitable mathematical formula, to Faraday rotation. The rotation is, then, plotted versus the square of the wavelength. The slope of the graph at longer wavelengths is directly proportional to the carrier concentration and the effective mass. With one known, the other can be easily determined.

Abstract: Nitrosyl fluoride is prepared by laser-induced method wherein the nitrosyl luoride is produced in situ or in close proximity to where it is used to etch semiconductor surfaces.A reaction mixture of a catalyst compound and a fluoro compound, wherein the catalyst compound is an oxide of nitrogen selected from the group of nitrogen oxide compounds consisting of NO, N.sub.2 O, and NO.sub.2 and wherein the fluoro compound is selected from the group of fluoro compounds consisting of NF.sub.3 and N.sub.2 F.sub.4, is irradiated with CO.sub.2 laser radiation to produce FNO. FNO reacts with an exposed silicon material to produce SiF.sub.4 and nitrogen oxide. Since the oxide is regenerated, it can be regarded as a catalyst which can be recovered and recycled.A production scheme for producing nitrosyl fluoride for etching is disclosed wherein the nitrosyl fluoride is produced directly in the laser reaction chamber by passing a CO.sub.2 laser beam through the reaction mixture.

Abstract: A CW tunable laser is employed in a laser photochemical decomposition met to achieve decomposition of a compound of high toxicity to relatively non-toxic decomposition products.Organophosphorus chemical agents containing a characteristic C--O--P group are irradiated with a predetermined power level from about 10 to about 150 W/cm.sup.2 for a predetermined time period to effect cleavage of the C--O bond. The infrared laser excitation level of radiation in the range of 10.4 .mu.m or 9.4 .mu.m is resonant with the absorption band of the C--O--P group contained in the organophosphorus chemical agent. The absorbed radiation effects cleavage of the C--O bond and thereby achieves decomposition of the organophosphorus chemical agent.The disclosed method is highly selective for cleavage of the C--O bond rather then cleavage of the P--O bond, and in the presence of air, the method requires low power levels of the CO.sub.2 laser for rapid and complete dissociation of the organophosphorus chemical agent.

Abstract: A cw CO.sub.2 tunable laser is employed to irradiate an allyl halide selected from allyl chloride, allyl bromide, allyl fluoride, 2-methyl-3-chloropropene, and 2,3-dichloropropene and contained in one or more reaction cells at a predetermined pressure. A predetermined power level from about 25 to 150 watts, an irradiating time from about 0.2 second to about 60 seconds, and a selected radiation line for example P(36), P(32), P(28), P(26), or P(22) (that is resonant with an absorption band of the selected allyl halide) are employed to achieve dissociation of the selected allyl halide and to achieve a laser-induced photochemical synthesis of benzene and substituted benzenes.