最大振荡频率640 GHz的70 nm栅长InAs PHEMTs器件

由于高的电子迁移率和二维电子气浓度，InP基赝配高电子迁移率晶体管（PHEMTs）器件成为制作太赫兹器件最有前途的三端器件之一。为提高器件的工作频率，采用InAs复合沟道，使得二维电子气的电子迁移率达到13000 cm2/（Vs）。成功研制出70 nm栅长的InP基赝配高电子迁移率晶体管，器件采用双指，总栅宽为30 m，源漏间距为2 m。为降低器件的寄生电容，设计T型栅的栅根高度达到210 nm。器件的最大漏端电流为1440 mA/mm （VGS=0.4 V），最大峰值跨导为2230 mS/mm。截止频率fT和最大振荡频率fmax分别为280 GHz和640 GHz。这些性能显示该器件适于毫米波和太赫兹波应用。

70 nm gate-length InAs PHEMTs with maximum oscillation frequency of 640 GHz

Because of the high electron mobility and two-dimensional electron gas concentration, InP based pseudomorphic high electron mobility transistors(PHEMTs) become one of the most promising three-terminal devices which can operate in terahertz. The InAs composite channel was used to improve the operating frequency of the devices. The two-dimensional electron gas(2DEG) showed a mobility of 13000 cm2/(Vs) at room temperature. 70 nm gate-length InAs/In0.53Ga0.47As InP-based PHEMTs were successfully fabricated with two fingers 30 m total gate width and source-drain space of 2 m. The T-shaped gate with a stem height of 210 nm was fabricated to minimize parasitic capacitance. The fabricated devices exhibited a maximum drain current density of 1440 mA/mm(VGS=0.4 V) and a maximum transconductance of 2230 mS/mm. The current gain cutoff frequency fT and the maximum oscillation frequency fmax were 280 and 640 GHz, respectively. These performances make the device well-suited for millimeter wave or terahertz wave applications.