ABSTRACT
The technology of solid-state integrated circuits (IC) has been continuously and steadily progressing since the 1940s, it was only in the early 1980s that its impact on silicon detectors fabrication became really important. Radiation detectors are normally fabricated on so-called ‘detector-grade’ silicon wafers. Low-resistivity substrates are quite different from Czochralski substrates, which are commonly used for IC fabrication, since high resistivity and high purity are their main characteristics. The sensors' fabrication on high-resistivity silicon substrates requires the creation of both p+ and n+ doped regions to process junctions and ohmic contacts. For electrical contacts to the junctions to be possible, openings have to be processed on the oxide surface. Oxide depositions prior to metallization can be performed at higher temperatures, with better results in terms of uniformity, step coverage, and a wider choice of possible reactions. Oxidation is a first step in silicon detector fabrication which is a relatively recent technology, emerged mainly for micro-electro-mechanical systems applications.
