Doping and radiation damage profiles of P+ions implanted in silicon along the [110] axis

Abstract

Several doses of 200 KeV phosphorus ions have been implanted under channeling conditions along the [110] direction in silicon. Range distribution has been determined for the three implant doses 10¹³, 10¹⁴, 10¹⁵ P⁺/cm² both with the electrical measurements and the neutron activation techniques. The radiation damage distribution has been determined both with 290 KeV proton back-scattering analysis and with transmission electron microscopy (TEM) observations. Good agreement has been found between electrical and neutron activation profiles in the samples where 100% of the implanted dose had been electrically activated by means of annealing. Carrier concentration profiles, from samples implanted with 10¹⁵ P⁺/cm², determined after two different annealing temperatures (500°C and 700°C) have bcen compared with the radiation damage distribution and a correlation between damage and phosphorus electrical activation process seems to be possible. Maximum damage peak, as determined by back-scattering analysis, shifts from ∼0.4 μ depth in the lower dose(5 × 10¹⁴ P⁺/cm²), to ∼0.22 pm depth in the higher implanted dose (4 × 10¹⁵ P⁺/cm²). Damage distribution of phosphorus ions random implanted in the same experimental conditions shows 3 peak at ∼0.2 μn depth. In accordance with the back-scattering analysis, T.E.M. observations on 10¹⁵P⁺/cm² implanted samples show the presence of amorphous regions at depth between 0.25 and 0.5 μm from the surface. In the most damaged layer ∼0.3μm in depth, a surface density of ∼10¹²/cm² amorphous regions 25-50 A diameter was observed.