Study of the characteristics of silicon MESA radiation detectors

The MESA process for building silicon diodes is described. I-V and C- V features of MESA detectors are given. Results of pulse-height spectra measurements with alpha particles incident on the front and back sides of a MESA diode establish the energy resolution of these detectors, show the evolution of their response as a function of applied bias voltage, and bring information about the influence of MESA structure on charge collection. The characteristics of MESA detectors as a function of fluence are investigated in view of their possible use in high particle fluence environment. Charge collection data obtained from the measurements of the current-pulse response induced by beta and alpha particles are presented as a function of applied bias voltage and particle fluence. Some electrical characteristics of detector material, namely the effective impurity or dopant concentrations (N/sub eff/), the electron ( mu /sub e/) and hole ( mu /sub h/) mobilities, are studied as a function of fluence using a charge transport model. A comparison is made with the features of standard planar (SP) silicon detectors. (7 refs).