RESUMEN
Electro-thermal annealing (ETA) in a MOSFET utilizes Joule heating. The high-temperature heat effectively cures gate dielectric damages induced by electrical stresses or ionizing radiation. However, even though ETA can be used to improve the reliability of logic and memory devices, applying ETA in state-of-the-art field-effect transistors (FETs) such as nanosheet FETs (NS FETs) has not yet been demonstrated. This paper addresses the heat distribution characteristic of an NS FET considering the application of ETA, using 3D simulations. A vacuum inner spacer is newly proposed to improve annealing effects during ETA. In addition, evaluations of the device scaling and annealing effect were performed with respect to gate length, nanosheet-to-nanosheet vertical space, and inner spacer thickness. Guidelines for ETA in NS FETs can be provided on the basis of the results.
RESUMEN
In contrast to conventional forming gas annealing (FGA), high-pressure deuterium annealing (HPD) shows a superior passivation of dangling bonds on the Si/SiO2 interface. However, research detailing the process optimization for HPD has been modest. In this context, this paper demonstrates the iterative impact of HPD for the better fabrication of semiconductor devices. Long-channel gate-enclosed FETs are fabricated as a test vehicle. After each cycle of the annealing, device parameters are extracted and compared depending on the number of the HPD. Based on the results, an HPD condition that maximizes on-state current (ION) but minimizes off-state current (IOFF) can be provided.
RESUMEN
PURPOSE: This study compared serum vascular endothelial growth factor (VEGF) concentration between patients given the bilateral and unilateral intravitreal injections of bevacizumab. METHODS: In a prospective manner, serum VEGF levels in treatment-naive patients with age-related macular degeneration who underwent bilateral or unilateral intravitreal injections of bevacizumab were investigated. After informed consent, peripheral blood was collected from in patients who underwent bilateral or unilateral intravitreal injection of bevacizumab before and 1 month after the injection. Serum VEGF levels were measured by enzyme-linked immunosorbent assay after centrifugation. In addition, best-corrected visual acuity (BCVA) and central retinal thickness (CRT) before and 1 month after the injection were compared between each group. RESULTS: Twenty patients received bilateral injections (40 eyes) and 20 patients received unilateral injections. The VEGF concentrations (pg/mL) before the bilateral injection were 235.75 ± 183.16 and 252.53 ± 233.52 for the unilateral injection. They were significantly reduced to 153.88 ± 113.26 and 189.42 ± 251.72 after 1 month, respectively (p = 0.037 and 0.019), which are showing no significant difference between the two groups (p = 0.771). And there were no significant intergroup difference in pre- and postoperative BCVA and CRT. CONCLUSIONS: The bilateral simultaneous intravitreal injection of bevacizumab did not differ greatly from unilateral intravitreal injection in the influence on serum VEGF levels and the therapeutic outcome.