Modeling of Ion Implantation Induced Damage in Silicon

15.02.2003 - 14.02.2007
Forschungsförderungsprojekt
Ion implantation is the primary technique in silicon technology for introducing dopant atoms into the substrate. As an unwanted side-effect, the crystal lattice is damaged which makes an annealing step necessary. Unfortunately, the generated defects cause transient enhanced diffusion of the dopants during anneal. This leads to the broadening of dopant profiles and, as a consequence, impedes device shrinkage. The amount of diffusion as well as the time and temperature necessary to anneal the defects depends on their number and type. Detailed understanding of the damage formation process and accurate models for simulation are therefore of great value to the design of silicon devices. The importance of this topic is illustrated by the International Technology Roadmap for Semiconductors having identified "implant damage, amorphization, and subsequent re-crystallization during anneal" as a difficult challenge in the field of modeling and simulation. The goal of this project is a more detailed understanding of damage formation in silicon and quantitative models of its dependence on implant parameters such as ion mass, dose, dose rate, and temperature. As simulation methods atomistic approaches are used (binary collision, kinetic Monte Carlo, and molecular dynamics simulations) which have become more popular in recent years because of the increase in available computer resources. Implantation experiments at cryogenic temperatures are performed to study collisional effects, at temperatures up to room temperature to study dynamic annealing, and under amorphizing conditions to study processes at existing amorphous/crystalline interfaces. As analytical techniques, Rutherford backscattering and channeling (RBS/C) is used to measure the total number of displaced atoms, and transmission electron microscopy (TEM) to study the damage morphology and to determine the position of the amorphous/crystalline interface. Special care is taken in RBS/C quantification to use accurate defect atom positions determined by ab-initio simulations. Dopant profiles generated by implantations into channeling direction and analyzed with secondary ion mass spectrometry (SIMS) are used to cross-check the RBS/C results.

Personen

Projektleiter_in

Institut

Grant funds

  • FWF - Österr. Wissenschaftsfonds (National) Austrian Science Fund (FWF)

Forschungsschwerpunkte

  • Modeling and Simulation: 100%

Schlagwörter

DeutschEnglisch
Siliziumtechologiesilicon technology
Ionenimplantationion implantation
Implantationsschädenimplantation damage
Atomistische Simulationsmethodenatomistic simulation methods
Rutherford backscatteringRutherford backscattering
Transmissionselektronenmikroskopietransmission electron microscopy

Externe Partner_innen

  • Johannes Kepler Universität Linz
  • Institut für Chemische Technologien und Analytik
  • Institut für Festkörperphysik
  • Universität Wien

Publikationen