Investigation of the diffusion parameters of the borosilicate-silicon system by infrared absorption

Abstract

The characteristic parameters of a solid-to-solid diffusion system are investigated. The net boron concentration of the pyrolytically deposited SiO2 films used as diffusion sources is determined by infrared spectrophotometry. The data of the diffused layer in Si are used to correlate the infrared absorption spectrum with the composition of the SiO2 films. The absorption cross section of the B-O oscillator is determined. The surface concentration and junction depth of the diffused layer in the Si are determined from the infrared absorption of the SiO2 film and by the four-point probe and bevelled-edge methods.

Comparison making use of IR absorption of the boron and phosphorus concentrations of SiO2films doped by pyrolysis and ion implantation

“…For P, only this choice of the interval led to meaningful results. Comparing our previous investigations (Hoffmann et al 1975) with the present one, two different values were obtained for the constant of the IR B concentration deterniination (AV = 10 cm-1) : KIB == (4.4 k 0.5) x 10l6 atons/cm2 was calculated from the diffused layer data according to Hoffmann ef aZ (1975) and &~=(3*5rt0.4)x 1016 atoms/cmz was obtained by the implantation of boron ions into the Si02 film.…”

“…The dopant concentrations of the films are directly proportional to the area under the absorption curves (Barrow 1962), i.e. the following equation is approximately valid (Hoffmann et al 1975): CO = KO 2 a(.) AV = A' C a(.)…”

Determination of the phosphorus content of doped SiO2films by IR absorption and activation analysis

“…The determination of the dopant concentration of an Si02 film deposited on to Si substrates using IR absorption has been dealt with by Hoffmann et al (1975Hoffmann et al ( , 1979. The precision of this method depends on the precision of the constant of the IR P determination.…”