SIMS and RBS Investigation of Zn Implanted Si

We present results of secondary ion mass-spectrometry and Rutherford backscattering spectroscopy of the Zn implantation profile in the damaged layer of a n-type Cz-Si(100) substrate, as well as the profile change during annealing. Si wafers were implanted with 64Zn+ ions at energy of 100 keV and ion dose of 2x1014cm-2. They were then subsequently annealed at 400 deg. C for 60 min and 700 deg. C for 10 min. Analysis of experimental data shows that in the as-implanted sample on a silicon surface a damage gauzy amorphous layer with thickness about 80nm was created, located inside the substrate at the ion-implantation depth. After two annealing steps the defects were completely annealed out. From the Zn depth profiles we observe that during annealing the Zn concentration decreases and the Zn peak concentration moves to the wafer surface. The Zn concentration maximum exceeds the solubility limit of Zn in Si, suggesting decomposition of Zn solid solution in Si and Zn precipitation.