Damage formation and annealing studies of low energy ion implants ...
Damage formation and annealing studies of low energy ion implants ... Damage formation and annealing studies of low energy ion implants ...
substitutional sites. The formation of the segregated peak, is clearly visible after the high temperature anneals at the depth indicated by MEIS (1.5– 2 nm). The SIMS results finally show the onset of As diffusion after 900 °C RTA, and after 1050 °C spike annealing. SIMS Concentration (cm -3 ) 10 23 10 22 10 21 10 20 10 19 10 18 3x10 21 2x10 21 1x10 21 Si 30 x 32 As 2.5 keV As 1.8E15 cm -2 0 5 10 15 20 25 30 0 0 5 10 Depth (nm) 15 6.2.3 PAI 3keV As implanted samples Experiments with comparable implantation and annealing conditions using Xe- PAI samples were also carried out and results of selected samples are presented here. They include a comparison with specular reflectivity (SR) measurements. The dopant 123 As (MEIS) Si 30 as-impl 600 C 10 s 700 C 10s 900 C 10s 1050 C spike Figure 6.2 (Top) SIMS As depth profiles for 2.5 keV 1.8E15 As implants, for various anneal temperatures. (Bottom) The same profiles are plotted with a linear concentration scale and smaller depth range. The MEIS profile from the as-implanted sample is included in the figure for comparison. 60 40 20 MEIS Yield (cts/5µC)
implantation conditions are those used for device manufacturing, i.e. a 3 keV As + implant to a fluence of 2E15 cm -2 . These implants have been carried out into crystalline Si (No PAI), and Si pre-amorphised with a 130 keV Xe + implant to a fluence of 2E14 cm -2 (PAI). This results in a Si amorphisation depth of 100 nm as measured with XTEM (13). The results obtained for two annealing conditions are presented here, these are furnace annealing at 600 °C for 20 minutes and spike annealing to 1130 °C. The sample after high temperature spike anneal is representative of current manufacturing methods. The results following the low temperature furnace anneal are included primarily for comparison with SR results. 6.2.3.1 MEIS results The MEIS analysis conditions used were a nominally 100 keV He + beam with the samples aligned along the [īīı] channelling direction relative to the beam. The analyser was positioned to record data along the [111] and [332] blocking directions. MEIS energy spectra from along the [111] blocking direction, for both PAI and NoPAI sample series, are shown in Figure 6.3. Also included in the figure for reference is a spectrum from a virgin Si sample and a random spectrum taken from an amorphous Si sample. Yield (counts per 5 µC) 450 400 350 300 250 200 150 100 50 0 O depth (nm) 6 4 2 0 3keV As 2E15 ion/cm 2 [111] Blocking direction Si depth (nm) 16 14 12 10 8 6 4 2 0 70 72 74 76 78 80 82 84 86 88 90 92 94 96 Energy (keV) 124 virgin Random 3 keV as-impl 3 keV 600C 20mins 3 keV 1130C spike 3 keV as-impl PAI 3 keV 600C 20mins PAI 3 keV 1130C spike PAI As depth (nm) 16 14 12 10 8 6 4 2 0 Figure 6.3 MEIS spectra collected along the [111] blocking direction. The non-implanted Si sample and a random amorphous Si spectrum are shown for comparison.
- Page 91 and 92: they are small compared to the diff
- Page 93 and 94: ackscattering (27). This fact forms
- Page 95 and 96: Figure 4.7 a) Plot of a Gaussian di
- Page 97 and 98: similar to the width of the error f
- Page 99 and 100: UP Ion Beam SPIN Rotation Sample Sc
- Page 101 and 102: Kinematic factor (K) 1.0 0.8 0.6 0.
- Page 103 and 104: Figure 4.14 Illustration of the dou
- Page 105 and 106: 4.2.2.4 Interpretation of spectra A
- Page 107 and 108: with are comparatively small, ~ 0.5
- Page 109 and 110: Inelastic energy loss (eV/Ang) 32 2
- Page 111 and 112: iterative procedure is carried out
- Page 113 and 114: Yield (couts per 5µC) 300 250 200
- Page 115 and 116: SIMS experiments were also carried
- Page 117 and 118: MEIS, using the scattering conditio
- Page 119 and 120: 4.5 Sample production Samples have
- Page 121 and 122: an N2/O2 environment to maintain an
- Page 123 and 124: 38 M. Anderle, M. Barozzi, M. Bersa
- Page 125 and 126: damage evolution behaviour observed
- Page 127 and 128: Yield (counts per 5 µC) 250 200 15
- Page 129 and 130: essentially a “zero dose” profi
- Page 131 and 132: no longer “visible” in MEIS has
- Page 133 and 134: yield (cts / 5µC) 500 400 300 200
- Page 135 and 136: 5.4 Conclusion MEIS analysis with a
- Page 137 and 138: Chapter 6 Annealing studies 6.1 Int
- Page 139 and 140: 6.2.2.2 Results and Discussion Figu
- Page 141: theory predictions and X-ray fluore
- Page 145 and 146: a) b) c) Yield (counts per 5 µC) Y
- Page 147 and 148: greater than MEIS. SIMS is not sens
- Page 149 and 150: attributed to the interference betw
- Page 151 and 152: The as-implanted sample, with a bro
- Page 153 and 154: a) b) Yield (counts per 5 µC) Yiel
- Page 155 and 156: interface, as evidenced by the high
- Page 157 and 158: duration, is observed. MEIS results
- Page 159 and 160: Yield (counts per 5µC) 500 400 300
- Page 161 and 162: ack edges of the Si peaks are very
- Page 163 and 164: underneath the SiO2 layer, iii) it
- Page 165 and 166: R s (Ω/sq) 950 900 850 800 750 60
- Page 167 and 168: As concentration (at/cm 3 ) 1E22 1E
- Page 169 and 170: R s (Ω/sq) 950 900 850 800 750 70
- Page 171 and 172: Following annealing it was observed
- Page 173 and 174: ∆a/a (x 10 -3 ) 4,0 epi550 3,5 3,
- Page 175 and 176: Yield (counts per 5 uC) 350 300 250
- Page 177 and 178: (FWHM). Concomitantly, As in the re
- Page 179 and 180: Yield (counts per 5 µC) 450 400 35
- Page 181 and 182: The higher temperature anneals carr
- Page 183 and 184: ecomes steeper for the sample annea
- Page 185 and 186: Figure 6.28 Schematic illustrations
- Page 187 and 188: and the 2D picture in Figure 6.31b)
- Page 189 and 190: 6.5 Conclusion In summary, in this
- Page 191 and 192: 20 L. Capello, T. H. Metzger, M. We
substitut<strong>ion</strong>al sites. The <strong>format<strong>ion</strong></strong> <strong>of</strong> the segregated peak, is clearly visible after the<br />
high temperature anneals at the depth indicated by MEIS (1.5– 2 nm). The SIMS results<br />
finally show the onset <strong>of</strong> As diffus<strong>ion</strong> after 900 °C RTA, <strong>and</strong> after 1050 °C spike<br />
<strong>annealing</strong>.<br />
SIMS Concentrat<strong>ion</strong> (cm -3 )<br />
10 23<br />
10 22<br />
10 21<br />
10 20<br />
10 19<br />
10 18<br />
3x10 21<br />
2x10 21<br />
1x10 21<br />
Si 30 x 32<br />
As<br />
2.5 keV As 1.8E15 cm -2<br />
0 5 10 15 20 25 30<br />
0<br />
0 5 10<br />
Depth (nm)<br />
15<br />
6.2.3 PAI 3keV As implanted samples<br />
Experiments with comparable implantat<strong>ion</strong> <strong>and</strong> <strong>annealing</strong> condit<strong>ion</strong>s using Xe-<br />
PAI samples were also carried out <strong>and</strong> results <strong>of</strong> selected samples are presented here.<br />
They include a comparison with specular reflectivity (SR) measurements. The dopant<br />
123<br />
As (MEIS)<br />
Si 30<br />
as-impl<br />
600 C 10 s<br />
700 C 10s<br />
900 C 10s<br />
1050 C spike<br />
Figure 6.2 (Top) SIMS As depth pr<strong>of</strong>iles for 2.5 keV 1.8E15 As <strong>implants</strong>, for various anneal<br />
temperatures. (Bottom) The same pr<strong>of</strong>iles are plotted with a linear concentrat<strong>ion</strong> scale <strong>and</strong><br />
smaller depth range. The MEIS pr<strong>of</strong>ile from the as-implanted sample is included in the<br />
figure for comparison.<br />
60<br />
40<br />
20<br />
MEIS Yield (cts/5µC)
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