The Properties and Sensing Mechanism of PdNPs-decorated Silicon Nanobelt Devices for H2 Sensing at Room Temperature

This study reports the properties and the sensing mechanism of Pd nanoparticles (PdNPs) decorated n+/n-/n+ double-junction silicon nanobelt (SNB) device as hydrogen (H2) gas sensor. The SNB devices are prepared via CMOS process. Plasma-enhanced atomic layer deposition (PEALD) is adopted for PdNPs deposition as sensing material on the Al2O3 dielectric of SNB devices. The PdNPs-decorated SNB devices working at room temperature are characterizedat H2 concentration ranging from 10 to 1000 ppm. Instead of using the traditional steady-state response, the slope of response is presented to estimate concentration and shorten the response time. More than 60% improvement in response time has been achieved for 10 to 1000 ppm H2 detection. To reduce recovery time, device localized Joule heating (DLJH) with a bias of 11 V for 240 s is demonstrated to restore the device back to the baseline.At a bias of 1 V, H2 sensing at room temperature consumes only 68.39 μW.

本项研究阐述了Pd纳米粒子（PdNPs）修饰的n+/n-/n+双结硅纳米带（SNB）器件作为氢气（H2）传感器的特性及其传感机理。该SNB器件通过CMOS工艺制备。采用等离子体增强原子层沉积（PEALD）技术，在SNB器件的Al2O3介电层上沉积PdNPs作为传感材料。室温下工作的PdNPs修饰的SNB器件在10至1000 ppm的H2浓度范围内进行了表征。不同于传统稳态响应，本研究以响应斜率作为估计浓度和缩短响应时间的指标。在10至1000 ppm的H2检测中，实现了超过60%的响应时间提升。为了降低恢复时间，通过施加11 V偏置电压并持续240秒的设备局部焦耳加热（DLJH）方法，将器件恢复至基线状态。在1 V偏置下，室温下进行H2传感仅需消耗68.39 μW的功率。