The electrical and physical properties of the ternary compound ZnO-B20:~-SiO2 glass/silicon interfaces were compared using the high frequency C-V curves of a MIS diode, differential thermal analysis (DTA) characteristics, SEM observation, x-ray diffraction, and secondary ion mass spectroscopy (SIMS) analysis, as a function of firing temperatures. It was revealed that effects of increasing firing temperatures on the glass/silicon systems were: (i) a crystallization in the glass layer which caused roughening of the silicon interface by the reaction of glass with silicon, and resulted in increased trapped charge density at the interface, N~,; and (ii) B impurity diffusion into the silicon from the glass which decreased the glass fixed charge density, Nf, so as to compensate for n-type silicon.The ternary ZnO-B203-SiO2 glass is used for passivation of power semiconductor devices. Because of its importance to these devices, a number of investigations have looked at the glass/silicon interface (1-4). Misawa (3) reported the presence of a negative or positive net number of charges in the glass layer could be ensured by controlling the firing temperature and glass composition. Murakami and co-workers (4, 5) investigated the reverse current-voltage characteristics of a zinc borosilicate glass passivated p-n junction in relation to the interfacial electrical factors. However, some ambiguities remain, for example, how does the chemical or physical history affect the electrical factors at the glass/silicon interface?The purpose of this work is to characterize the glass/ silicon interface electrically and structurally using a zinc b0rosilicate glass/silicon system, with special emphasis on the effects of the glass firing temperatures. We used a SEM photomicroscopic observation of the glass/silicon interface, optical photomicroscopy of the silicon surface with the glass layer removed, differential thermal analysis (DTA) to characterize the thermal properties of the glass itself, and x-ray diffraction to investigate crystallization of the fired glass layer. In addition, secondary ion mass spectroscopy (SIMS) was employed to identify the impurities at the silicon surface. Based on these experimental results, we proposed a new concept to explain the kinetics of the crystallization of the glass layer and its effect on the interfacial electrical characteristics as a function of firing temperatures. ExperimentalSample prepara~ion.--Silicon wafers used in the experiments were 8 -+ 0.2 tl cm, 228 -+ 2 ~m thick, phosphorus-doped n-type substrate with (111) orientation. Sample preparation was done as follows. The silicon wafer surface was chemically etched by ID etchant [HNO3:HF:CH3COOH:iodine liquid (27g I2 dissolved in 2100 cm 3 CH3COOH) = 135:40:65:15 volume ratio] for 5s and then cleaned in deionized water. An electrophoretic method was used to deposit glass powders of ZnO [65 weight percent (w/o)], B203 (25 w/o), and SiO2 (10 w/o) composition on the clean surface. Firing was then carried out in an oxygen atmosphere at temperatures ...
The physical origins of negative fixed charges at the lead glass/silicon interface have been studied. It was found that a thin p-type region is present on the n-type substrate in the PbO-SiO2-Al2O3 glass/silicon system from the punch-through voltage, pinch-off voltage, and SIMS analysis. A new model of the negative fixed charge was proposed from the MIS structure with the surface pn junction.
A single crystal of indium antimonide (zinc blende type InSb) was evaluated as an X-ray monochromator. The long 2d spacing of 7.481 A makes it possible to diffract Si K a in an ordinary X-ray emission spectrometer. The indium antimonide data were compared with crystals of EDDT, Gc and LiF. Indium antimonide shows seven times higher Si Ka intensity than EDDT. It also has very low second order reflcction. A low coefficient of thermal expansion (4.9 X lo-' " C ' ) , together with its very stable chcmical nature will facilitate high precision measurement ranging from ''Si to 4hPd(Kcu), 38Sr to 9 2 U ( L~) and 74W to "U(Ma).
The effects of hydrogen annealing on lead glass/silicon systems with negative charges N have been studied. It was found that a positive shift in the negative N contributed to decreasing the leakage current of mesa-type glass passivated p-n junction and that a PDZ (Pb denuded zone) was formed at the glass surface by hydrogen annealing. A high selective catalyst Pd deposition method prior to electroless Ni plating was established by removing catalyst poison Pb lumps at the glass surface and has succeeded in high-quality electroless Ni plating of surface mounted diode.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.