Study of IR absorption and photoconductivity spectra of thermal double donors in silicon

Abstract

PACS 71.55.Cn, 78.20.Ci, 78.30.AmThe IR absorption and photoconductivity spectra of a double donor (TDD) family with ionization energies less than 70 meV in silicon were investigated using Fourier transform spectroscopy with a resolution down to 0.25 cm -1 . The values of line frequencies, widths, splitting and absorption cross sections for transitions from the ground to p-states (including high-excited states) were obtained. Determination of absorption cross sections was made using Hall data and concerted changes of boron and TDDi concentrations caused by neutralization of impurities under band gap illumination.Introduction Oxygen-containing thermal donors in Si along with B and P are widespread impurityrelated centers in Cz-Si. Investigations of the structure, energy spectrum and formation kinetics of various families of thermal donors have been carried out by various methods of IR spectroscopy [1 −3]. At the same, time only one work is known in which the absorption cross sections for transitions 1S → 2P 0 at a maximum of the lines for six thermal double donors have been determined in experiments with a low resolution [4]. In this report the results of detailed studies of IR absorption and photoconductivity spectra of TDDs with ionization energies less than 70 meV are given.

"New Donors" in Czochralski Grown Silicon Annealed at T≥ 600°C under Compressive Stress

“…Moreover, before taking IR spectra the heat-treated samples were illuminated with band gap light in the course of their cooling from room temperature down to cryogenic temperatures in order to transform all the bistable TDD1 and TDD2 species into the atomic configuration with the two normal donor states indicated above; see for instance [1]. On a basis of the known calibration factors for the electronic transitions at TDDs as well as shallow donor and acceptor centers [10] it is possible to convert the intensities of the relevant absorption lines into concentrations of the centers under consideration.…”

Development of the conductivity type inversion caused by thermal double donors’ formation in p-type high-resistivity silicon

“…It is well known that TDDs are small electrically active clusters of oxygen. [18][19][20][21][22][23][24] The formation of TDDs was observed by electrical and optical techniques. [25][26][27][28] TDDs are generated during annealing in the temperature range of 300 °C-550 °C and the maximum formation rate of TDDs was observed at 450 °C.…”