Laser-annealed ohmic contacts for GaAs microwave devices

Microstructure and Resistivity of Laser‐Annealed Au‐Ge Ohmic Contacts on GaAs

“…As is described elsewhere (1), the dopant incorporation process in a silane/arsine epitaxial system requires several minutes to regain steady state when a perturbation such as a step change in dopant gas flow is imposed on the reactor. Similarly, the dopant incorporation process requires several minutes to reach the expected steady-state condition at the beginning of the deposition step (2). Consequently, the epitaxial dopant concentration reaches the expected doping level only for films thicker than that corresponding to this initial transient.…”

“…The dopant incorporation process has been the subject of previous investigations (1)(2)(3)(4). The work presented here deals primarily with the silicon deposition * Electrochemical Society Active Member.…”

“…Recent research has focused on using laser irradiation for making ohmic contacts to GaAs because the localized, short duration heating of a laser beam was expected to result in negligible GaAs decomposition and therefore improve contact quality. Results obtained for laser-annealed ohmic contacts (1,2) have so far shown no significant improvement in contact properties over contacts made by conventional furnace alloying. A more detailed study of laser-annealed ohmic contacts, focusing on the materials properties, therefore seems necessary.…”