Analysis of Write-Beam-Induced Damage on the Conducting PRIZ (Preobrasovatel Izobrazheniya)

The susceptibility of the conducting PRIZ to write beam induced damage was studied. Using a HeCd laser as a write beam, damage was intentionally induced on PRIZ devices. Careful examination of the devices revealed essentially four types of damage: electrode damage, pit damage, striation, and crack damage. Striation may have been a pattern of overlapping less severe crack damage. The write beam irradiance and applied E field strength were varied in search of damage thresholds, and analysis was performed to discover the location and nature of the damage. Electrode damage was in the form of either evaporation or migration. Pit damage, striation, and crack damage were related: all occurred in the high field region of the PRIZ, i.e. near the negative surface; all displayed a symmetric structure resembling the corner of a cube (pits displayed this structure only after chemical etching); and, although striation and cracks did not always appear with pit damage, pits always accompanied striation and crack damage. On one surface of a crystal, dense patches of pits and striation were induced, while on the other surface, crack damage and fewer pits resulted. This was found to be due to a difference in the surface imperfections caused by the mechanical preparation of the crystals. (Theses).