Plasma-enhanced chemical-vapor deposition (PECVD) with the surface irradiated by a 193 nm, 50 Hz pulsating laser was performed to synthesize boron films from B2H6+He at a pressure of 200 Pa, where the plasma was employed to generate precursor radicals for the growth while the irradiation was intended for photochemical enhancement of the surface processes such as migration and growth reactions. In addition to the PECVD, PECVD without the irradiation as well as pyrolytic CVD with and without the irradiation were done so as to clarify the effects of the plasma and the laser in the CVD. Micromorphological boron columns were found to grow toward the laser light, and this indicated directly that the surface growth reactions were enhanced photochemically at the laser energy density of 170 mJ/cm2 per pulse. Heating of the surface by the irradiation at this energy density was estimated to be negligible. In the pyrolytic CVD, where the surface migration of the precursor radicals was considered to be relatively hindered according to measured activation energies, a morphological change was found to indicate irradiation-enhanced migration at the laser energy density of 3 mJ/cm2 per pulse. Semiempirical molecular orbital calculations predicted that borane molecules (BH3) should be the dominant precursor in the pyrolytic CVD while the counterpart could be BH2 radicals in the PECVD: This prediction supports a hypothetical photoinduced growth reaction such as BH*2+ nhν = B(s) + H2 (n=1,2, ...) where BH*2 signifies a BH2 radical chemisorbed to a site for growth reaction and B(s) does a boron atom incorporated into the solid structure. This prediction was also consistent with the experimental result that crystalline boron films have grown only in the PECVD while the pyrolytic CVD yielded only amorphous growth at substrate temperatures between 690 and 890 °C. The predicted precursor BH3 for the pyrolytic CVD suggested its photoinduced migration mechanism similar to the photolysis of diborane.

Cubic boron nitride (CBN) crystallites have been grown by plasma enhanced chemical vapour deposition from BCl3+NH3+H2+Ar under the irradiation of an ArF excimer laser at 193 nm, at substrate temperatures of between 500 and 900 degrees C, on Si(100) surfaces; the energy density for a laser pulse was 18-24 mJ cm-2. The lattice parameter a of the polycrystalline part, measured by transmission electron diffractometry, was found to be 3.62 A, which is in fairly good agreement with the standard data available, i.e. 3.6158 A. A few micrometre-sized crystallites, with a morphology originated from a four-fold symmetry in the crystal structure, were found by scanning electron microscopy; these are considered to be CBN crystallites with their (100) planes parallel to the Si(100) according to the law of Bravais, being consistent with the recent report on heteroepitaxial growth of CBN film on the Si(100) by a laser-ablation method.

The sintering of ceramic oxide powders has been investigated using a high power CO2 laser as the heat source. The laser sintering method is very useful for the densification of oxides such as ZrO2, HfO2, and Y2O3 which have high melting points above 2000 °C. The new ceramic in the ternary system of (ZrO2-Y2O3-HfO2) processed by the laser method has a high melting point (2850 °C) and a hardness of about 1800 kg/mm2. The new oxide ceramic is composed of the crystalline phase of tetragonal ZrO2 and ZrO2 HfO2 Y2O3 solid solution, and does not show any phase transitions at high temperatures.

By using a newly designed collimated plasma beam reactor, plasma-enhanced chemical vapor deposition from BCl3+NH3+H2+Ar with the surface irradiated by a 193-nm excimer laser at a pressure of 2.8 Torr and substrate temperatures of 500–900 °C yielded BN films with the following texture as revealed by transmission electron diffractometry (TED), transmission electron microscopy, scanning electron microscopy, and Fourier-transformed infrared spectroscopy: (1) a thin-film part which consists of 10-nm-sized crystallites with a sp2-bonded structure grown on the substrate, namely, a sp2 100 Å layer; (2) polycrystalline parts with cBN or wBN structure, depending on the condition, embedded in a sp2 100 Å layer; (3) crystallites, though found infrequently, grown to be much larger than the sp2 100 Å layer thickness. The TED pattern of the polycrystalline wBN was particularly in agreement with the standard data.

Micromorphological boron columns were found to grow toward 193 nm light in a low-pressure B2H6+He plasma, as a direct evidence of a photoinduced growth. Its growth mechanism was discussed; the micromorphological growth rate which resulted from photoinduced growth reactions reflects a grading distribution of laser intensity on the initial hemispherical nucleus surface. Activation energies for the growth were positive in the plasma-enhanced chemical vapor deposition while they were negative in the pyrolysis; this was discussed based on a previously proposed growth model.