Enhanced Electrical Activation in In-Implanted Si_0.35Ge_0.65 by C Co-Doping

Figures & data

Figure 1. (a) Resistivity, (b) carrier density and (c) carrier mobility as a function of In concentration. Squares and circles represent In-doped Si_0.35Ge_0.65 [6] and C + In co-doped Si_0.35Ge_0.65, respectively. In panel (b), un-bracketed and bracketed numbers are the electrically active fractions for In-doped Si_0.35Ge_0.65 [6] and C + In co-doped Si_0.35Ge_0.65, respectively.

Figure 2. The Fourier-transformed, k²-weighted EXAFS spectra as a function of radial distance for (a) the In-doped Si_0.35Ge_0.65 [6] and (b) C + In co-doped Si_0.35Ge_0.65 samples, respectively.

Table 1. A summary of the quantified fractions (from Figure 2) of In atoms in substitutional sites (S), metallic In (M), random lattice location (R) and substitutional sites pairing with C (C) of the In [6] and C + In-implanted Si_0.35Ge_0.65 samples.

		EXAFS
	In (and C) concentration (at%)	S fraction (%)	M fraction (%)	R fraction (%)	C fraction (%)
In-doped Si0.35Ge0.65^a	0.02	100	0	∼	∼
	0.06	74 ± 4	26 ± 4	∼	∼
	0.2	33 ± 2	67 ± 2	∼	∼
	0.6	∼	81 ± 4	19 ± 4	∼
C + In-doped Si0.35Ge0.65	0.02	100	0	∼	∼
	0.06	100	0	∼	∼
	0.2	25 ± 13	0	∼	75 ± 13
	0.6	∼	67 ± 3	33 ± 3	∼

^a[6].

Figure 3. Cross-sectional TEM images for (a) 0.2 at% In doped Si_0.35Ge_0.65 and (b) 0.2 at% C + In co-doped Si_0.35Ge_0.65.