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The whole-core transport code nTRACER has made many advances in recent years. Several innovative cross section treatment methods were developed, a new axial transport solver was introduced for stabilizing the 2D/1D scheme, and substantial computational enhancements were achieved using NVIDIA CUDA and Intel Math Kernel Library (MKL). In addition, gamma transport solver was implemented to predict the power distributions more physically, and the flexibility of the restart calculation was improved using an offline processing code nTIG (nTRACER Input Generator). This paper is the compilation of the recent progresses in nTRACER developments.

Thin-film transistors (TFTs) with a small pitch size are necessary to realize high-resolution displays for virtual reality and augmented reality applications. Particularly, electrodes require low-resistance metals to reduce the resistance–capacitance delay caused by the increased pixel density. However, low-resistance Al can easily oxidize in bottom-contact structures of vertical TFTs owing to the oxidative deposition environment. This study quantitatively analyzed the contact properties of an Al-based metal with Mo and Ti capping layers. The Mo/Al/Mo and Ti/Al/Ti were adopted as the source/drain (S/D) electrodes, and their contact properties were compared. The top-gate bottom-contact device with Mo/Al/Mo S/D exhibited better contact properties, with a 0.02 V turn-on voltage (Von), 3.5 × 107 ON/OFF ratio, and 5.7 kΩ contact resistance (RSD). By contrast, the device with Ti/Al/Ti S/D exhibited degraded characteristics, with a −0.3 V Von, 0.9 × 107 ON/OFF ratio, and 17 kΩ RSD owing to metal oxidation. The contact properties were further examined through ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Vertical TFTs were fabricated using Mo/Al/Mo and Ti/Al/Ti electrodes, and their electrical properties were investigated. The vertical TFT with Mo/Al/Mo electrodes exhibited reasonable performance, with a field-effect mobility of 3.3 cm2 V−1 s−1 and RSD of 15 kΩ. Conversely, the device with Ti/Al/Ti electrodes yielded degraded transfer characteristics, with a mobility of 0.05 cm2 V−1 s−1 and RSD of 984 kΩ. The analysis indicates that electrode materials significantly influence the electrical performance of vertical TFTs. Therefore, electrode materials must be carefully selected and structured to realize high-end vertical TFT arrays. [ABSTRACT FROM AUTHOR]