PYROELECTRIC DETECTOR FOR PARTICLE BEAMS

For ion beams used for ion beam etching and sputtering in electronic device technology and for monitoring plasma wall interactions, a pyroelectric detector has been developed to measure the current density of neutralized ions and the fraction of the total beam which is neutralized. The pyroelectrically induced charges due to beam heating of a PVDF film and the deposited charge from the ion beam are measured with a charge sensitive and current sensitive amplifier, respectively. The pyroelectric detector has a sensitivity of 1000 V/W and 1/e response time of 2 s. Beam current densities in the range 0.01-100 muA/cm2 of 1 keV particle energy can be measured.