Investigation on indium diffusion in silicon

Abstract

The diffusion of indium in silicon has been investigated in the temperature range of 800 to 1000 °C by using secondary ion mass spectroscopy and transmission electron microscopy. Our data indicate that, for implants at 150 keV through a thin oxide layer (19 nm), the amount of dopant that leaves the silicon is only controlled by the flow of indium that reaches the surface, being both the segregation coefficient at the interface SiO2/Si and the indium diffusion coefficient in the oxide favorable to the out-diffusion. Comparison between experimental and simulated profiles has evidenced that, besides the expected transient enhanced diffusion occurring in the early phases of the annealing, a heavy loss of dopant by out-diffusion was associated with a high In diffusivity near the surface. Measurements of the hole concentration in uniformly doped silicon on insulator samples performed in the temperature range of 700 to 1100 °C indicate that indium solubility is equal or greater than 1.8×1018 cm−3; this value is higher than those previously proposed in literature.

Indium penetration through thermally grown silicon oxide

“…The intrinsic diffusion parameters of indium in silicon are well established [3]. TED of indium in silicon was also investigated [5,12]. However, there was no information about the diffusion of indium in polycrystalline silicon.…”

“…For the samples with indium implantation into the silicon substrate, implantation damage generated excess interstitials. Such excess interstitials promoted indium diffusion, causing transient enhanced diffusion (TED) [5,12]. TED caused some indium atoms to migrate from the silicon substrate into the thin oxide.…”

“…However, significant segregation and out-diffusion of indium have been observed [2e6]. The diffusion coefficient of indium in oxides must be adjusted to match the dose loss of indium in silicon [5]. Recently, n-type InGaAs MOSFETs were fabricated on silicon substrates using thick silicon oxides for device isolation [7].…”

Communication—Anomalous Shift of the Capacitance-Voltage Characteristics Obtained for p-MOS Capacitors with a Tin-Doped Indium Oxide Gate

“…The indium diffusivity into silicon dioxide has been reported to be sufficiently high. 12,13 Moreover, an abnormal shift of C-V characteristics has been reported for Au-SiO 2 -Si capacitors after applying a low-temperature (up 400…”

Fabrication and Thermal Budget Considerations of Advanced Ge and InP SOLES Substrates

“…Given indium's solid solubility in Si of only ∼1e18 cm −3 , 29 and segregation coefficient of between ∼0.1 and 0.001 in this temperature range studied here, 28,30 indium remains in the SiO 2 over Si. The lack of In diffusion into the Si device layer is advantageous for the CMOS devices which would be processed on this Si layer.…”