ION-IMPLANTATION DOPING AND ELECTRICAL-PROPERTIES OF HIGH-TEMPERATURE LADDER POLYMERS

We report the first ion implantation doping studies on high-temperature ladder polymers and show that insulating films of the benzimidazobenzophenanthroline type ladder polymer (BBL) can be doped by boron, argon, and krypton implantation to conductivities as high as 224 S/cm at a dose of 4. 0 multiplied by 10**1**6/cm**2 while retaining the excellent mechanical properties of the pristine films. Effects of dose (ions/cm**2) and beam current density (microamps/cm**2) on electrical conductivity at fixed ion energies are reported. The temperature dependence of the conductivity indicates that the implanted ladder polymer films are semiconductors. Spatially selective implantation, creating regions of conducting lines in an insulating matrix, which suggests microelectronic device applications of the ladder polymers, is demonstrated.