Concentration Study of Deep-Level Cu Center in Cu-Diffused Si Crystals by Deep-Level Transient Spectroscopy and Photoluminescence Measurements

Abstract

The differential incoherent scattering cross sections of 320 kev photons by K-shell electrons of lead, tantalum and samarium are experimentally determined employing a fast-slow coincidence scintillation spectrometer by the degraded photon Kx-ray coincidence technique at angles of scattering 45", 60", 90" and 110'. T h e results are compared with the computed values and the trends of the incoherent scattering function are discussed.

Diffusion-Temperature-Dependent Formation of Cu Centers in Cu-Saturated Silicon Crystals Studied by Photoluminescence and Deep-Level Transient Spectroscopy

“…4. The ratios are not constant but decrease as the diffusion temperature increases from 1.3% at 600 C to about 0.007% at 1000 C. For the samples diffused with dilute Cu (< 1 Â 10 15 cm À3 ) at 700 C, the concentration ratios were almost constant at about 2%, 20) which can be clearly extrapolated from the curve for the ratios shown in Fig. 4.…”

“…The linear relationship between the concentration of the center and that of dissolved Cu in the crystal 11,20) should also be taken into account. From this relationship together with the law of mass action, we propose that the center contains one unique Cu atom that forms stable bonds at a special site.…”

Deep-Level Transient Spectroscopy and Photoluminescence Studies of Formation and Depth Profiles of Copper Centers in Silicon Crystals Diffused with Dilute Copper

“…The method of DLTS measurement was the same as that described previously. 11) Before forming the electrodes, the sample surfaces were rinsed with 0.5% HF solution. Ti Schottky barrier electrodes of 100 nm thickness and 1 mm diameter were formed by evaporation on one side of the samples and a 1-mm-thick Al metal layer was deposited over each Ti electrode by evaporation.…”

“…The concentration of the Cu DLB center is almost constant at ð1:2 {1:8Þ Â 10 13 cm À3 at temperatures between 450 and 700 C. The marked decrease in the intensity of the peak H(50) and the low intensity of the peak H(185) are seen at 800 C. The sum concentration of the peaks H(50) and H(185) at that temperature is extremely low compared with those for the samples diffused at other temperatures. The concentration of the peak H(185) in the sample diffused at 1000 C is as large as those of the peak H(50) in the samples diffused between 450 and 700 C. Since the Cu DLB center is the same species as the 1.014 eV Cu PL center, 9,11) the DLTS concentration and PL intensity of the center should have analogous dependences on the diffusion temperature. The circles in Fig.…”

“…10) The determination of Cu concentration in Si crystals can be possible by measuring these centers with DLTS and PL methods. 11) However, basic investigations, such as those on the effect of the diffusion temperature of Cu on the formation of Cu centers and the uniformity of the centers in the depth direction, have rarely been carried out. For Si crystals saturated with Cu, the formation of the Cu centers in the bulk was studied for a wide range of diffusion temperatures, and the Cu DLB center was the main species throughout the diffusion temperature range studied.…”