Glass passivation in power rectifiers. / Passivação a vidro de junções semicondutoras em dispositivos de potência.
AUTOR(ES)
Fabiana Lodi Marzano
DATA DE PUBLICAÇÃO
2006
RESUMO
The search for better electrical properties, new passivating materials for semiconductors junctions and the process of obtaining those ones have being studied intensively in the latest decades. There are two types of passivation layers: thick film and thin film. The first one is obtained by the deposition of silicon oxides, silicon nitride or silicon carbide, while in the second one is obtained through the application of silicon rubber or glass over the exposed juntion. The decision of using one or another depends on cost/benefit and desired electrical properties of the devices. In the semiconductor power industry the thick films are frequently used because the devices dimensions are large and the cost of these processes are cheaper than those of thin films. Silicon rubber and glass are widely used by this industry. The silicon rubbers are materials that show temperature resistance up to 2000C. The inorganic glasses are more stables at high temperatures. In this work we developed a process of glass passivation for power semiconductors devices, controlled this process and it is in use in a production line of a semiconductor power device industry. There are a few glasses for this application where the two more widely used are Al-B-Pb-Si glass and Zn-B-Si glass. In this work it was compared the influence of the glass chemical composition as well as frit grain size of the glass, over the breakdown voltage and leakage current of the devices. It was observed that glasses of Al-B-Pb-Si with smaller grain size gave better values of breakdown voltage with a production yield bigger up to 33%. It was obtained leakage current values of the same magnitude, at ambient temperature, for both kinds of glasses with different grain sizes and composition.
ASSUNTO(S)
silício glass semicondutores passivation diode vidro diodos
