Dopant deactivation in heavily Sb doped Si (001): A high-resolution x-ray diffraction and transmission electron microscopy study
Abstract
Laser annealing is being studied as an alternative dopant activation technique to form the ultrashallow, low resistivity junctions required in future generations of integrated circuits. This method benefits from the ability to create uniform, box-shaped dopant profiles with concentrations that can exceed equilibrium solubility values. These supersaturated dopant concentrations, however, exist in a metastable state and deactivate upon subsequent thermal processing. Electrical measurements show that antimony deactivation becomes increasingly severe as the concentration increases. High-resolution x-ray diffraction (HR-XRD), secondary ion mass spectroscopy and transmission electron microscopy were used to study the deactivation process. Under most conditions, Sb deactivation occurs through the precipitate mechanism in which the inactive dopant forms precipitates, leading to a decrease in the substitutional dopant concentration. However, the HR-XRD data reveal that at high concentrations above 6.0×1020 cm-3 during low temperature anneals, the inactive dopant forms a type of inactive structure that resides on a substitutional site within the Si matrix.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- November 2002
- DOI:
- 10.1063/1.1510953
- Bibcode:
- 2002JAP....92.5503T
- Keywords:
-
- Additives;
- Antimony;
- Crystal Defects;
- Doped Crystals;
- Electrical Resistivity;
- High Resolution;
- Impurities;
- Integrated Circuits;
- Laser Annealing;
- Mass Spectra;
- Mass Spectroscopy;
- Secondary Emission;
- Semiconductors (Materials);
- Silicon;
- Transmission Electron Microscopy;
- X Ray Diffraction;
- 61.72.Tt;
- 61.72.Cc;
- 81.05.Cy;
- 82.80.Ms;
- 61.72.Ss;
- Solid-State Physics;
- Doping and impurity implantation in germanium and silicon;
- Kinetics of defect formation and annealing;
- Elemental semiconductors;
- Mass spectrometry;
- Impurity concentration distribution and gradients