This paper is devoted to an electrochemicaletchingbased technology for fabricating highperformance MODFET's for highspeed applications. The electrochemical etching in the gate openings is induced by the exposure of the Ni surface metal on the ohmic electrodes. It results in very slender gaterecess grooves which are desirable for highspeed MODFET's because of the resulting achievable small gatetochannel separation and low parasitic resistance. The technology is easy to implement and is effective for enhancing the aspect ratio. Good control of aspect ratio is essential for achieving excellent device performance and limiting deleterious shortchannel effects. Successful vertical scaling together with minimization of gate length by wellestablished electronbeam lithography using fullereneincorporated electronbeam resist leads to the realization of both optimal D and Emode MODFET's with ultrahigh extrinsic transconductance values and current gain cutoff frequencies. Fully passivated 0.07nm DMODFET's with 2.25 S/mm extrinsic transconductance and current gain cutoff frequency exceeding 300 GHz have been successful fabricated. In addition 0.03|m EMODFET's with 2 S/mm transconductance and 300 GHz current gain cutoff frequency have been demonstrated. This electrochemicaletchingbased technology provides both highperformance D and EMODFET's and therefore opens up the possibility to achieve ultrahighspeed IC's based on DCFL configurations.
|ジャーナル||IEEE Transactions on Electron Devices|
|出版ステータス||Published - 2000 12月 1|
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