4 - Physical and Chemical Deposition of Metals as Ohmic Contacts to InP and Related Materials

Abstract

This chapter summarizes the current knowledge regarding the technology for manufacturing ohmic contacts to InP-based materials. The correlation between the metallurgical phenomena and process parameters, and the contact electrical properties is emphasized. Stable and robust metallization schemes for ohmic contacts have always been important in order to assist an excellent short and long term performance of the devices. The more advanced the devices, the more are the demands imposed on the ohmic contact technology such as, low surface damage deposition, ultra-pure metal-semiconductor interfaces, high temperature deposition of stable stress-free ultra-thin films, and excellent current conductance, which are the key features for the manufacturing of advanced device contacts. This chapter also describes some advanced and new conceptual approaches and introduces the idea of integrated contact manufacturing process by means of rapid thermal low pressure chemical vapor deposition technique. Much more work is still required to tune-up these advanced concepts and to turn them successfully from a research and development feasibility demonstration to a real wide-scale manufacturing concept.