Gettering Technology for CMOS Image Sensors Using a Cluster Ion Implantation

Proximity gettering technology for advanced CMOS image sensors using carbon cluster ion‐implantation technique: A review

“…In contrast, the hydrogen peak concentration decreased after epitaxial growth and after CMOS heat treatment. These were very surprising results, because it has been established that hydrogen can diffuse out to the wafer surface from the hydrogen projected range during CMOS heat treatment . Thus, most of the hydrogen atoms diffused to the silicon wafer surface.…”

“…This technique can implant a silicon wafer surface simultaneously with carbon and hydrogen elements that form the projection range by using a hydrocarbon compound gas source. In our previous study , it was found that a carbon cluster ion implanted silicon wafer had three characteristics for high performance of advanced CMOS image sensors. First, a carbon cluster ion projection range has high gettering ability of metallic impurities during heat treatment .…”

Dissociation Kinetics of Trapped Hydrogen in High-dose Hydrocarbon-Molecular-Ion-Implanted Silicon during Rapid Thermal Annealing

“…To resolve the above technical issues, we developed an epitaxial silicon wafer in which we introduced proximity gettering sinks by a hydrocarbon molecular ion implantation technique [15,16]. Kurita and coworkers presented three unique characteristics of a hydrocarbon-molecular-ion-implanted epitaxial silicon wafer to improve the electrical device performance of CMOS image sensors [17][18][19][20][21][22]. First, the hydrocarbon-molecularion-implanted region has high gettering capability for various heavy metallic impurities [17][18][19][20][21][22][23][24][25].…”

“…Kurita and coworkers presented three unique characteristics of a hydrocarbon-molecular-ion-implanted epitaxial silicon wafer to improve the electrical device performance of CMOS image sensors [17][18][19][20][21][22]. First, the hydrocarbon-molecularion-implanted region has high gettering capability for various heavy metallic impurities [17][18][19][20][21][22][23][24][25]. The gettering technique has been widely used as a processing technique that can eliminate heavy metallic impurities diffused to the device active region during CMOS device fabrication process in semiconductor manufacturing.…”

“…This technique can markedly improve electrical device performance such as pn-junction leakage current, oxide breakdown voltage characteristics, and white spot defect density by capturing the metallic impurity at gettering sites formed outside the device active region during CMOS device fabrication process [26]. Second, this implanted region also has a diffusion barrier to prevent oxygen impurities diffusing out to the device active region from the silicon substrate during the fabrication of CMOS image sensors [17][18][19][20][21][22]. Third, hydrogen in hydrocarbon molecular ions trapped in the ion-implanted region diffuses to processinduced defects such as interface state defects at the SiO 2 /Si interface and is expected to cause the passivation effect [17-22, 27, 28].…”