| AVS 59th Annual International Symposium and Exhibition | |
| Surface Science | Wednesday Sessions |
| Session SS+OX-WeM |
| Session: | Synthesis and Characterization of Oxides |
| Presenter: | R. Shyam, Clemson University |
| Authors: | R. Shyam, Clemson University E.S. Srinadhu, Clemson University S. Chambers, Clemson University J.E. Harriss, Clemson University W.R. Harrell, Clemson University C.E. Sosolik, Clemson University |
| Correspondent: | Click to Email |
We have fabricated metal-oxide-semiconductor (MOS) devices for a study of implantation rates and damage resulting from low energy ion-solid impacts. Specifically, we seek to capture ion irradiation effects on oxides by exposing as-grown SiO2 layers (50 nm to 200 nm) to incident beams of singly-charged alkali ions with energies in the range of 100 eV to 5 keV. The oxide is analyzed post exposure by encapsulating the irradiated region under a top metallic contact or within a finished MOS device. Characterization of the resulting ion-modified MOS device involves the standard techniques of room temperature and bias-temperature stress capacitance-voltage (C-V) measurements. The C-V results reveal alkali ion-induced changes in the flatband voltage and slope of C-V of irradiated devices which can be used to extract and delineate between implantation probabilities and irradiation effects of the ions. Biased C-V measurements are utilized to confirm the concentration or dosage of ions in the oxide. A triangular voltage sweep (TVS) measurement at elevated temperatures also reveals the total ionic space charge in the oxide and is used to extract mobility for the ions as they pass through the damaged oxide. Our C-V data show changes in flatband voltage which are greater than those expected for mobile charges present at the range calculated by SRIM which implies that stoichiometry, morphological and chemical changes in the SiO2 layer are introduced by the ion impacts.