Fundamental Characteristics of Cyanide‐Related Multielement Molecular Ion‐Implanted Epitaxial Si Wafers for High‐Performance CMOS Image Sensors

Abstract

Fundamental characteristics such as metal‐gettering capability and defect morphology of a cyanide‐related multielement molecular (CH4N) ion‐implanted epitaxial silicon (Si) wafer are investigated. It is found that the CH4N ion‐implanted epitaxial Si wafer has a higher gettering capability for transition metallic impurities than a hydrocarbon molecular (C3H5) ion‐implanted epitaxial Si wafer. This higher metal‐gettering capability of the CH4N ion‐implanted epitaxial Si wafer may be due to the formation of stacking faults as well as carbon (C) agglomeration defects in the CH4N ion‐implanted region during the epitaxial Si layer growth process. The formation of stacking faults may be a specific phenomenon in the case of the CH4N ion implantation. In addition, the CH4N ion‐implanted region can trap high concentrations of hydrogen (H) and nitrogen (N) atoms during the epitaxial Si growth. This fact suggests that the distribution of N atoms is strongly associated with the defect morphology and C distribution in the CH4N ion‐implanted region. The CH4N ion‐implanted epitaxial Si wafer with these characteristics has the potential to improve the performance of complementary metal‐oxide‐semiconductor (CMOS) image sensors.

Thermally Robust High‐Resistance Layers on Low‐Resistance Silicon Synthesized by Molecular CO+ Ion Implantation

“…The authors showed that carbon atoms formed SiC precipitates, whereas oxygen or nitrogen atoms are responsible mainly for the extended defect formation. [ 6–10 ] They did not investigate the oxygen or nitrogen atom roles in the silicon oxide and nitride gettering properties.…”

“…[5] Further improvement of epilayer properties has been demonstrated recently by the multielement molecular ion implantation in Cz-Si wafers before the thick epitaxial layer overgrowth. [6][7][8][9][10] These authors implanted molecular hydrocarbon (C x H y ), methyloxidanyl (CH 3 O), or cyanide (CH 4 N) molecular ions at moderate fluences (1-5) Â 10 15 cm À2 as the related multielement gettering layers. They proved successful gettering in the implanted layers of not only metal impurities such as Fe or Cu, but even hydrogen atoms at 10 18 cm À3 concentration after silicon epitaxial layer overgrowth and furnace annealing at 1100 C. The authors showed that carbon atoms formed SiC precipitates, whereas oxygen or nitrogen atoms are responsible mainly for the extended defect formation.…”

“…They proved successful gettering in the implanted layers of not only metal impurities such as Fe or Cu, but even hydrogen atoms at 10 18 cm À3 concentration after silicon epitaxial layer overgrowth and furnace annealing at 1100 C. The authors showed that carbon atoms formed SiC precipitates, whereas oxygen or nitrogen atoms are responsible mainly for the extended defect formation. [6][7][8][9][10] They did not investigate the oxygen or nitrogen atom roles in the silicon oxide and nitride gettering properties.…”

Thermal Shrinkage Behavior of CH3O-Multielement-Molecular-Ion-Implantation-Induced Dislocation Loops Studied by Real-Time Transmission Electron Microscopy Observation

“…33 In the CH 3 O-ion-implanted epitaxial Si wafers, in addition to C x Si y precipitates, dislocation loops lying on the {111} planes are formed in the ion projected range. 32,34 Hence, the most significant difference between the CH 3 O-ion-implanted and hydrocarbon-molecular-ion-implanted epitaxial Si wafers is whether or not the extended defects are generated. The generation of dislocation loops in a multielement-molecular-ionimplanted Si wafer is attributed to the including of O atoms in the molecular ion.…”

In Situ Transmission Electron Microscopy Study of Shrinkage Kinetics of CH4N-Molecular-Ion-Implantation-Induced Extended Defects

“…21 In addition, for further enhancement of the CIS performance, we have been developing a novel functional CH 4 N-molecular-ion-implanted epitaxial Si wafer. 22 The CH 4 N ion implantation technique enables the implantation of nitrogen (N) in addition to H and C. The CH 4 N-ion-implanted epitaxial Si wafer has a high density of EOR defects as well as C x Si y precipitates in the ion projected range. 22 We previously demonstrated that the CH 4 N-ion-implanted epitaxial Si wafer also has a high gettering capability for metals and light element impurities (H, C, N, and O).…”