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A p·ZnSnAs2/n·ZnSe heterodiode was prepared by LPE from Sn solution on a low-resistivity n·ZnSe substrate. The I-V characteristics of the diode were measured, and it was found to have a good rectification ratio of 104 at 1 V. The diode showed a photoresponse extending over a wide wavelength region between 0.4 and 1.9 µm. The measurements of the C-V characteristics showed that the diode had an abrupt junction with a diffusion potential of 0.60 V. The dielectric constant for ZnSnAs2 was first estimated from the analysis of the C-V characteristics: ε A =12.0ε 0. The values of the minority carrier lifetime were obtained from the decay curves of EBIC as 70 ns and 0.4 ns for n·ZnSe and p·ZnSnAs2, respectively.

Heteroepitaxy of CuInS2 has been carried out on ZnSe by the LPE method from an In solution. The optimum growth conditions were a maximum temperature T m of 700°C and a cooling rate CR of 0.5°C/min. LPE growth was not successful when T m was 500–650°C. The critical value of T m for successful LPE growth was near 700°C. The coefficient k LPE defined as the ratio of the optimum T m to the melting temperature of the solute, was than those for other chalcopyrite materials investigated previously. The optimum growth conditions are considered to be related to the energies of formation and melting temperatures of the substrate and solute, and the I2-VI, III2-VI3 and other compounds produced in the LPE system.

A metal-oxide-semiconductor (MOS)-LSI chip was designed by the 0.8 µm rule, and a passivated film on the chip was etched off while keeping the chip mounted on a ceramic package. The acoustic signal generated by irradiation of a chopped electron beam was picked up by a piezoelectric detector (PZT element) attached to the back of the package. The results of observation by electron-acoustic microscopy (EAM) are as follows: (a) the observable depth (t x) was proportional to the electron range (R e); (b) t x shifted to a shallower side (about 50% of R e) compared to the case of bipolar transistors; (c) contact holes (0.8 µm2) were distinctly observed at HV=19 kV; and (d) the resolution of our EAM was estimated to be about 0.4 µm at a chopping frequency of the electron beam of 1 MHz and an acceleration voltage of 18–19 kV.