Rapid Thermal Annealing of Nuetron Transmutation Doped Czochralski Silicon
- PDF / 453,519 Bytes
- 7 Pages / 420.48 x 639 pts Page_size
- 52 Downloads / 240 Views
RAPID ThHMIAL ANNEALING OF NUJTRON TRANSKJTATION DOPED CZDCHRALSKI SILIXON G.M. BEREZINA, F.P. KDRSHUNOV, N.A. SOBOLEV, A.V. VOEVODOVA, and A.A. SlUK Institute of Solid State and Semiconductor Physics, 220072 Minsk, ul. P. Brovki 17, Rep. of Belarus ABSTRACT The influence of the rapid thermal annealing (RTA) in comparison with that of the standard furnace annealing (FA) on the electrical parameters and photoluminescence (PL) of Czochralski silicon (Cz Si) subjected to neutron irradiation at various temperatures has been studied. The role of the irradiation temperature on the annealing behaviour of electrical parameters in CZ Si has been established. The possibility of getting neutron transmutation doped (NTD) Cz Si having the calculated resistivity by means of the RTA is shown. INTRODUCTION The basic starting material used in the NTD technology of silicon is that grown by the floate zone (FZ) technique. This is caused by the fact that in the course of long term FA of neutron irradiated Cz Si various types of excess oxygen donors stable in the temperature range 350 to 1000-C are created [1]. The aim of the present paper is to investigate the possibility of obtaining NTD Cz Si with required resistivity by means of neutron irradiation and RTA.
EXPERIMENTAL Samples of FZ (series No.1) and Cz (series No's 2, 3, 4) grown n-Si were subjected to neutron irradiation in a water reactor with a cadmium ratio of 10:1. Samples No's 2 & 4 were cut frcm the same ingot and irradiated to two different fluences. Samples of the series No. 3 were cut from another ingot but with parameters nearly identical to those of the series No's 2 & 4. Parameters of all samples are given in the Table. The samples No's 1 & 3 were irradiated together and the samples No's 2 & 4 in another run. Irradiated samples were subjected to the RTA by means of tungsten halogen lamps with the pulse duration of 20 s in the taperature range 500 to 1130CC or to the conventional FA for 15 min in the same temperature interval. PL at 4.2 K in the near band edge spectral region (1.17 - 1.0 eV) and Hall effect measurenents were used for the characterization of radiation defects (RD's) and shallow doping impurities.
RESJLTS Immediately after neutron irradiation all samples had a high resistivity (1E4 - lE5 Ohm. an) due to the conductivity compensation by RD's. In the PL spectra of the samples No's 2 & 4 the lines X(1.0398 eV) and W(1.018 eV) tcgether with some other weak features were observed prior to annealing (fig. 2a). The spectra of the two series are very similar. It follows fram the caqparison of the temperature regions in which these centers exist [2] that the samples No's 2 & 4 were heated during irrradiation to 250 - 300oC. In the PL spectra of the samples No's 1 & 3 the W line is absent (and only a very weak X line is present in the sample No. 3), instead several other lines, i.e. M5, 7, 29, 64, 65 (and in addition Mat. Res. Soc. Symp. Proc. Vol. 262. 01992 Materials Research Society
732
TABLE Sample No. 1 2
: Qo, Ol'm.am 1E3
:
N(O),
am-3 1E16 8E17
:
Data Loading...
