This work reports the fabrication, characterization and testing for pH sensitivity of dielectric modulated MOS-HEMT(Metal oxide semiconductor- high electron mobility transistor) devices for bio-sensing applications. The primary aim here is to develop high sensing devices for bio-detections. The oxide based gate area is used in ensuring the device performance through pH detection done prior to packaging and metal probing. Device parameters; gate length L _G , gate width W _G , gate spacing from source-drain ends, L _SG and L _GD have been varied to investigate the effect on pH sensitivity. The HEMT stack with AlN spacer has been grown through MOCVD (Metal-Organic Chemical Vapor Deposition) technique with no intentional doping on Si (silicon) substrate. Commercial buffer samples for pH values of 4, 7, 9.2 have been used to test the devices using drop casting technique. Drain current (I _D ) based sensitivity analysis shows that the device having ( $\text{L}_{{\text {SG}}} = 4\,\,\mu \text{m}$ , $\text{L}_{{\text {G}}} = 3\,\,\mu \text{m}$ and $\text{L}_{{\text {GD}}} = 18\,\,\mu \text{m}$ ) exhibits a maximum sensitivity of 3.361 mA/pH. The devices exhibit exemplary performance when device dimensions meet the following constraints i.e. L _SG : minimum, L _G : moderate and L _GD > 2*L _SG . Average sensitivities attained is in the range 1.69 mA/pH for a device with $\text{L}_{{\text {G}}} = 3\,\,\mu \text{m}$ , $\text{L}_{{\text {SG}}} = 2\,\,\mu \text{m}$ and $\text{L}_{{\text {GD}}} = 6\,\,\mu \text{m}$ .

中文翻译：

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用于生物传感应用的 MOS-HEMT 尺寸变体的制造和 pH 敏感性分析。

这项工作报告了用于生物传感应用的介电调制 MOS-HEMT（金属氧化物半导体 - 高电子迁移率晶体管）器件的 pH 敏感性的制造、表征和测试。这里的主要目标是开发用于生物检测的高感测设备。基于氧化物的栅极区域用于通过在封装和金属探测之前完成的 pH 检测来确保器件性能。设备参数；栅极长度 L _G ，栅极宽度 W _G ，与源漏端的栅极间距， L _SG和 L _GD已经改变以研究对 pH 敏感性的影响。带有 AlN 隔离层的 HEMT 堆栈是通过 MOCVD（金属有机化学气相沉积）技术生长的，没有在 Si（硅）衬底上有意掺杂。pH 值为 4、7、9.2 的商业缓冲样品已用于使用滴铸技术测试设备。 基于漏极电流 (I _D ) 的灵敏度分析表明该器件具有 ( $\text{L}_{{\text {SG}}} = 4\,\,\mu \text{m}$ , $\text{L}_{{\text {G}}} = 3\,\,\mu \text{m}$ 和 $\text{L}_{{\text {GD}}} = 18\,\,\mu \text{m}$ ) 的最大灵敏度为 3.361 mA/pH。当器件尺寸满足以下约束即L _SG ：最小，L _G ：中等并且L _GD > 2*L _SG时，这些器件表现出示例性的性能 。获得的平均灵敏度在 1.69 mA/pH 范围内 $\text{L}_{{\text {G}}} = 3\,\,\mu \text{m}$ , $\text{L}_{{\text {SG}}} = 2\,\,\mu \text{m}$ 和 $\text{L}_{{\text {GD}}} = 6\,\,\mu \text{m}$ .