Open AccessGettering Sinks for Metallic Impurities Formed by Carbon-Cluster Ion Implantation in Epitaxial Silicon Wafers for CMOS Image Sensor
Author(s) -
Ayumi Onaka-Masada,
Ryosuke Okuyama,
Satoshi Shigematsu,
Hidehiko Okuda,
Takeshi Kadono,
Ryo Hirose,
Yoshihiro Koga,
Koji Sueoka,
Kazunari Kurita
Publication year - 2018
Publication title -
ieee journal of the electron devices society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.69
H-Index - 31
ISSN - 2168-6734
DOI - 10.1109/jeds.2018.2872976
Subject(s) - components, circuits, devices and systems , engineered materials, dielectrics and plasmas
Gettering sinks for metallic impurities formed by carbon-cluster ion implantation in epitaxial silicon wafers have been investigated using technology computer-aided design and atom probe tomography (APT). We found that the defects formed by carbon-cluster ion implantation consist of carbon and interstitial silicon clusters (carbon-interstitial clusters). Vacancy-type clusters are not dominant gettering sinks for metallic impurities in the carbon-cluster ion implanted region. APT data indicated that the distribution of oxygen atoms in the defects differs between Czochralski-grown silicon and epitaxial silicon wafers. The high gettering efficiency observed in carbon-cluster ion implanted epitaxial silicon wafers in comparison with Czochralski-grown silicon wafers is due to the distribution of oxygen atoms in the defects. Defects not containing O atoms provide strong gettering sinks for metallic impurities. These defects are formed by only carbon-interstitial clusters. Oxygen atoms inside the defects modify the amount of carbon-interstitial cluster formation on the defects. It is suggested that the gettering efficiency for metallic impurities in carbon-cluster ion implanted epitaxial silicon wafer is determined by the amount of carbon-interstitial clusters.