NUMERICAL-SIMULATION OF ELECTRON-BEAM-INDUCED GATE CURRENTS IN A GAAS-MESFET .2. NUMERICAL AND EXPERIMENTAL RESULTS

Metal-semiconductor field-effect transistors (MESFETs) are important s emiconductor devices, which can be produced on many semiconductor mate rials. Owing to their simple structure, MESFETs are often used as pion eering devices when new material systems are developed. Electron-beam- induced gate current (gate EBIC) measurements in a scanning electron m icroscope (SEM) can be used as an important tool for investigating the electrical homogeneity of semiconductor materials, electrical contact s and process-induced defects in MESFETs. Furthermore, in combination with suitable simulations, a profound understanding of the importance of different material and device parameters to the electron-beam-induc ed currents is possible. With this aim, results of two-dimensional num erical gate EBIC simulations obtained for a GaAs MESFET are presented in this paper and partially compared with measured line scans.