Abstract
Positron annihilation in Si is a quantitaive, depth-sensitive technique for the detection of vacancylike defects or voids. A sensitivity of 5×1015 cm-3 for voidlike defects is easily achieved. The technique has been applied to a study of point-defect distributions in thin films of Si grown by molecular-beam epitaxy. A special procedure was developed to remove the influence of the native oxide on the positron measurement. 200-nm-thick films grown at temperatures between 475 and 560°C show no defects below the sensitivity limit and are indistinguishable from the bulk substrate. So are films grown at 220°C, provided a 2-min high-temperature anneal to a peak temperature of 500°C is executed every 30 nm during growth. If TRTA=450°C, part of the film contains vacancylike defects to a concentration of 1018 cm-3. These results correlate well with current-voltage characteristics of p-n junctions grown with different rapid thermal anneal (RTA) temperatures. Ion scattering, with a defect sensitivity of 1%, shows no difference between films grown with different TRTA. Recrystallization of amorphous films, deposited at room temperature and annealed in situ at 550°C, always leaves a significant defect concentration of 2×1018 cm-3; those defects are reduced but still present even after a 2-h 800°C furnace anneal.
| Original language | English |
|---|---|
| Pages (from-to) | 5345-5353 |
| Number of pages | 9 |
| Journal | Physical Review B |
| Volume | 48 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 1993 |
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ASJC Scopus subject areas
- Condensed Matter Physics
Cite this
Distribution of point defects in Si(100)/Si grown by low-temperature molecular-beam epitaxy and solid-phase epitaxy. / Asoka-Kumar, P.; Gossmann, H. J.; Unterwald, F. C.; Feldman, Leonard C; Leung, T. C.; Au, H. L.; Talyanski, V.; Nielsen, B.; Lynn, K. G.
In: Physical Review B, Vol. 48, No. 8, 1993, p. 5345-5353.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Distribution of point defects in Si(100)/Si grown by low-temperature molecular-beam epitaxy and solid-phase epitaxy
AU - Asoka-Kumar, P.
AU - Gossmann, H. J.
AU - Unterwald, F. C.
AU - Feldman, Leonard C
AU - Leung, T. C.
AU - Au, H. L.
AU - Talyanski, V.
AU - Nielsen, B.
AU - Lynn, K. G.
PY - 1993
Y1 - 1993
N2 - Positron annihilation in Si is a quantitaive, depth-sensitive technique for the detection of vacancylike defects or voids. A sensitivity of 5×1015 cm-3 for voidlike defects is easily achieved. The technique has been applied to a study of point-defect distributions in thin films of Si grown by molecular-beam epitaxy. A special procedure was developed to remove the influence of the native oxide on the positron measurement. 200-nm-thick films grown at temperatures between 475 and 560°C show no defects below the sensitivity limit and are indistinguishable from the bulk substrate. So are films grown at 220°C, provided a 2-min high-temperature anneal to a peak temperature of 500°C is executed every 30 nm during growth. If TRTA=450°C, part of the film contains vacancylike defects to a concentration of 1018 cm-3. These results correlate well with current-voltage characteristics of p-n junctions grown with different rapid thermal anneal (RTA) temperatures. Ion scattering, with a defect sensitivity of 1%, shows no difference between films grown with different TRTA. Recrystallization of amorphous films, deposited at room temperature and annealed in situ at 550°C, always leaves a significant defect concentration of 2×1018 cm-3; those defects are reduced but still present even after a 2-h 800°C furnace anneal.
AB - Positron annihilation in Si is a quantitaive, depth-sensitive technique for the detection of vacancylike defects or voids. A sensitivity of 5×1015 cm-3 for voidlike defects is easily achieved. The technique has been applied to a study of point-defect distributions in thin films of Si grown by molecular-beam epitaxy. A special procedure was developed to remove the influence of the native oxide on the positron measurement. 200-nm-thick films grown at temperatures between 475 and 560°C show no defects below the sensitivity limit and are indistinguishable from the bulk substrate. So are films grown at 220°C, provided a 2-min high-temperature anneal to a peak temperature of 500°C is executed every 30 nm during growth. If TRTA=450°C, part of the film contains vacancylike defects to a concentration of 1018 cm-3. These results correlate well with current-voltage characteristics of p-n junctions grown with different rapid thermal anneal (RTA) temperatures. Ion scattering, with a defect sensitivity of 1%, shows no difference between films grown with different TRTA. Recrystallization of amorphous films, deposited at room temperature and annealed in situ at 550°C, always leaves a significant defect concentration of 2×1018 cm-3; those defects are reduced but still present even after a 2-h 800°C furnace anneal.
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U2 - 10.1103/PhysRevB.48.5345
DO - 10.1103/PhysRevB.48.5345
M3 - Article
VL - 48
SP - 5345
EP - 5353
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 8
ER -