A novel polysilicon field-enhanced nanowire thin-film transistor with the TiN-hafnia-nitride-vacuum-silicon (THNVAS) structure for nonvolatile memory applications.

A novel poly-Si field-enhanced nanowire (FEN) TFT memory with the TiN-hafnia-nitride-vacuum-silicon (THNVAS) structure fabricated simply via a sidewall spacer formation has been presented. The THNVAS devices with superior memory performance were demonstrated by introducing the hafnia as blocking oxide and the vacuum, the lowest-k in nature, as tunneling layer. According to the simulation results, the memory device with oxide/nitride/vacuum gate dielectric exhibited a higher local electric-field of 4.72 x 10(7) V/cm as compared to 2.55 x 10(7) V/cm for the conventional oxide/nitride/oxide counterpart. In addition, the electric-field of tunneling layer could be further increased to 7.06 x 10(7) V/cm while the blocking oxide was substituted for hafnia. The experimental data showed that THNVAS possessed a greater threshold voltage shift of 3.75 V in 10 ms at V(GS) = 12 V, whereas the shift only 2.5 V for THNOS ones. These considerable improvements for THNVAS devices could be attributed to the evident field enhancement across the vacuum tunneling layer. Furthermore, owing to the empty feature of vacuum tunneling layer, the THNVAS demonstrated much-improved endurance performance and preferable data retention property. Hence, such excellent characteristics of THNVAS will be an attractive nonvolatile memory for future system-on-panel and 3-D Flash applications.

Nodular gastritis: an endoscopic indicator of Helicobacter Pylori infection.

We prospectively assessed the relationship between nodular gastritis and Helicobacter pylori infection. Of 1409 adults who underwent endoscopy for persistent dyspepsia between June 2004 and August 2005, 41 (2.9%) patients were diagnosed with nodular gastritis (11 [27%] men and 30 [73%] women). The mean age was 45.9 years. A control group of 65 patients without nodular gastritis was also evaluated. The prevalence of H. pylori infection was higher in patients with nodular gastritis than in controls (38/41 [93%] vs. 33/65 [51%]). Of 21 patients treated to eradicate H. pylori, the nodular gastritis pattern resolved or improved in 16 patients on subsequent endoscopy. This study suggests that a nodular pattern of the gastric mucosa on endocscopy is a good indicator for H. pylori infection in adults, with the high positive predictive value of 92.7%.