Diffusion kinetic of hydrogen in CH₃O-molecular-ion-implanted silicon wafer for CMOS image sensors

Abstract

The association and dissociation behavior of hydrogen in the implanted region of a CH 3 O cluster were investigated for high-performance CMOS image sensors. Two hydrogen peaks were observed in the CH 3 O-implanted region after epitaxial growth and heat treatment. The difference in the depths of the two peaks accords with the difference in the depth of carbon-cluster-related and new extended stacking fault defects. Thus, we calculated the activation energies of the association and dissociation of hydrogen, assuming a dissociation reaction for the first peak, formed at a small depth from the surface of the silicon substrate, and a simple reversible reaction for the second peak, formed at a large depth from the surface of the silicon substrate. The dissociation activation energy corresponding to the first peak was 0.75 + 0.03 eV. This activation energy indicates that the hydrogen associated with the first peak forms a binding state with a carbon and silicon self-interstitial cluster (C/I cluster). On the other hand, the binding energy corresponding to the second peak was calculated to be 0.78 eV, which was close to the C-H 2 binding energy. Consequently, the CH 3 O-implanted region forms a binding state with hydrogen and a C/I cluster or a C-H 2 binding state.

Proximity Gettering Design of Hydrocarbon–Molecular–Ion–Implanted Silicon Wafers Using Dark Current Spectroscopy for CMOS Image Sensors

“…Third, we demonstrated that the hydrogen out-diffused to silicon epitaxial layer (device active region) from hydrogen storage in hydrocarbon–molecular–ion projection range during the heat treatment [35,65,66]. This hydrogen of out diffusion amount is 10 12 to 10 13 cm −2 measured by SIMS after heat treatment [70]. It is well known that Si/SiO 2 interface state density in MOS transistor device is approximately 10 10 to 10 11 cm −2 [71].…”

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

“…Therefore, the shallower peaks in the H, C, and N profiles correspond to C/I clusters, and the deeper peaks correspond to stacking faults. Okuyama and coworkers reported that H at high concentrations can be trapped in C 3 H 5 and CH 3 O ion‐implanted regions by C/I clusters and/or stacking faults immediately after the epitaxial growth of the Si layer . Therefore, the existence of high concentrations of H atoms in the CH 4 N ion‐implanted region may also be responsible for the C/I clusters and stacking faults.…”

“…Okuyama and coworkers reported that H at high concentrations can be trapped in C 3 H 5 and CH 3 O ion-implanted regions by C/I clusters and/or stacking faults immediately after the epitaxial growth of the Si layer. [14,34] Therefore, the existence of high concentrations of H atoms in the CH 4 N ion-implanted region may also be responsible for the C/I clusters and stacking faults. In addition, there is a possibility that N atoms also segregate around the C/I clusters and stacking faults with H and C atoms.…”

Hydrogen Termination Effect on SiO2/Si Interface State Density in CH3O-Molecular-Ion-Implanted Silicon Epitaxial Wafer for CMOS Image Sensors

“…[37][38][39] 30 We used L 2 = 1.3 × 10 −12 exp (−0.75/kT) cm 3 /s reported in a previous study. 30 We tried to derive L 1 by fitting with the experimental results of D it heat-treatment time dependence. Figure 6 shows the result of fitting the D it plots using Eq.…”

“…29 It has also been reported that the hydrogen concentration in the CH 3 O-molecular-ion implanted region increases owing to the endof-range (EOR) defects. 30 Therefore, CH 3 O-implanted wafers are expected to have a better hydrogen termination effect than hydrocarbon-molecular-ion-implanted wafers. It is essential to reduce D it at the SiO 2 /Si interface to reduce the noise in high-performance CMOS image sensors in the future.…”