Method for making gradational diffusion photoelectric diode by using MOCVD epitaxial system

• Main Authors: TANG QI, QIN LONG, WU RUIHUA
• Format: Patent
• Language: Chinese; English
• Published: 15.12.2010
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

The invention relates to a method for making a gradational diffusion photoelectric diode by using an MOCVD epitaxial system. The method comprises the following steps performed on a semi-insulating indium phosphide substrate by using the MOCVD epitaxial system: performing the primary epitaxy of the photoelectric diode; forming an indium gallium arsenide ohmic contact layer; doping by using an MOCVD epitaxial system-based gradational diffusion method; making a pseudo-table by using a method combining reactive ion etching and chemical wet etching; making a second step by using a chemical wet etching method; making a SiO2 passivation layer and a photosensitive surface; evaporating an etching electrode; thinning the substrate and performing back sputtering and electrode alloying. Zinc phosphide is continuously generated during the diffusion and the method has the advantages of high doping, low ohmic contact resistance and high responsibility; moreover, abrupt junctions are formed during the diffusion, the dark cur