Structural changes in ion-implanted and rapid thermally annealed Si(100) wafers studied by spectroscopic ellipsometry

Abstract

The structural changes in P+ ion-implanted and rapid thermally annealed Si(100) wafers have been studied using spectroscopic ellipsometry (SE). The P+ ion implantation was performed at 150 keV with a fluence of 2 × 1015 cm−2 at room temperature. The rapid thermal annealing was carried out at 600°C in a dry N2 atmosphere for durations between t = 5 and 100 s. A model dielectric function (MDF), which was developed for modelling the optical properties of perfectly crystalline semiconductors, has been applied to study the optical properties of the ion-implanted and annealed layers. The experimental SE data have been successfully interpreted by the MDF with properly changing the critical point parameters from the perfectly crystalline values. The recrystallization is found to occur from an amorphous/crystalline interface with a rate of ∼340 Å s−1 at the initial annealing stage (t ⩽ 5 s) and ∼13 Å s−1 at the subsequent annealing stage (t > 5 s). The amorphous/crystalline phase transition is also found to occur at t ∼80–90 s. SE has been demonstrated to be an easy, fast and nondestructive technique, which can be used to assess important structural parameters in ion-implanted and annealed layers.

IR variable angle spectroscopic ellipsometry study of high dose ion-implanted and annealed silicon wafers

“…1 During the IC processing, ion implantation is the predominant method of doping to alter the electrical properties. 9,10 In this case, the SE measurement should be performed in infrared range, where the spectra are dominated by free carrier induced optical absorption and refractive index change. 2 Evaluating the distribution of the implanted ions and the activated impurities after implantation and annealing is essential for the semiconductor device design and fabrication.…”

Observation of resonant exciton and correlated plasmon yielding correlated plexciton in amorphous silicon with various hydrogen content

“…Discrete excitons are represented by n = − 1. The information obtained from the line-shape analysis can be compared with band structure calculations 40 – 42 .…”

Optical properties of N+ ion-implanted and rapid thermally annealed Si(100) wafers studied by spectroscopic ellipsometry

“…By monitoring the CP parameters, thus, we can conclude whether an ion-implanted material is still in the crystalline state or not 32 or, similarly, whether an ion-implanted and subsequently annealed sample is still in the amorphous state or not. 33 If a turning point in the CP parameter vs ion fluence or annealing time plot is observed, it may indicate the onset of crystalline/amorphous phase transition. The difference in the electronic properties between c-Si and a-Si has been discussed in detail by Thorpe and Weaire 34 and by Joannopoulos and Cohen.…”