RTA Diffusion

Simulation of 10 seconds boron diffusion at 1000 ºC after ion implantation at 2 keV with a dose of 1.0 x 10¹⁴ cm^-2 (Experiment is from B. Colombeau’s doctoral thesis). This type of simulation is extremely difficult because it needs to take into account several competing phenomena including strong defect recombination at the surface and very fast generation and recombination of various pairs and defect clusters. Nonetheless, advanced diffusion models in Athena 1D show quite good agreement with experimental profiles.

Low-Temperature Transient Enhanced Diffusion

Simulation of 35 minutes boron diffusion at 800°C after ion implantation at 20 keV with a dose of 1.0 x 10¹⁴ cm^-2 (Experiment is from S.Solmi et.al). This simulation and experiment show that even below the solid solubility level substantial portion of dopant remains inactive due to formation of mixed dopant-defect clusters. Due to inclusion of a sophisticated Boron Interstitial Cluster (BIC) model Athena 1D accurately predicts this important effect.

Oxidation

Simulation of Boron diffusion in an oxidizing ambient. Point defects are injected into the silicon with a rate that is a function of the rate at which the silicon is oxidizing. This point defect injection gives rise to an increased diffusion that is commonly referred to as Oxidation Enhanced Diffusion (OED). TWO.DIM model captures this effect by coupling point defects (interstitial and vacancy), generated by the oxidizing Si-SiO2 interface, with the diffusing boron.

The figure on the left shows the effect of the interstitiel injection coefficient THETA.0 for calibration of Oxidation Enhanced Diffusion.

Aluminium Implants into 6H-SiC

Monte Carlo simulation of Al implants into 6H-SiC at 30, 90, 195, 500 and 1000 keV with doses of 3.0 x 10¹³, 7.9 x 10¹³, 3.8 x 10¹⁴, 3.0 x 10¹³ ions/cm². The implants were 9° off-axis to avoid channeling. SIMS data are taken from Hernandez-Mangas, et.al. Journal of Applied Physics, v.91, pp.658--667, 2002.

The figure on the left depicts simulation results using MC Implant and compares them to measured data. The lines are MC Implant simulation profiles; diamonds represent SIMS profiles. Experimental and calculated depth profiles of phosphorus implanted at 100KeV, tilt = 0o and different doses in the range of 10¹³ cm^-2 to 10¹⁵ cm^-2. Experiments are compiled from R.J. Schreutelkamp et al., “Channeling Implantation of B and P in Silicon”, Nuclear Instruments and Methods, B55, pp. 615–619, 1991.

Effect of Oxide Thickness on Boron Implant Profiles

The figure on the left compares 35 keV, 1.0 x 10¹³ ions/cm², on-axis boron implantation performed through different thicknesses of grown oxide. These simulations use the SIMS-Verified Dual Pearson (SVDP) analytical model based on the tables from the University of Texas at Austin.