35nmInPHEMT FORMILLIMETERAND SUB-MILLIMETER WAVE APPLICATIONS

A newInPHEMT process hasbeendeveloped with35nmgatelength andimproved Ohmiccontact. A gate-source capacitance of0.4pF/mm isachieved withthereduced gatelength, a3000improvement overourbaseline 70nm device. Thecontact resistance issuccessfully reduced to0.07withthenewlydesigned contact layer combined with analloyed Au/Ge/Ni/Au Ohmicmetal. Gooddevice characteristics hasbeendemonstrated withatransconductance ashighas2S/mmandacutoff frequency fTof420GHz. A single-stage common-source amplifier wasfabricated withthis newprocess. A peakgain of5dBismeasured at265GHz. A MAG/MSGof3dBat300GHzwasachieved, makingthedevice suitable forapplications atfrequencies wellinto themillimeter-wave andevensub-millimeterwaveband. Thenextgeneration ofimaging andcommunication (Vistec LeicaEBPG5000/EBPG5). Wetchemical etching is technologies, operating inthemillimeter (mmW)andsub- subsequently usedtoforma single gaterecess.Finally, millimeter wave(sub-MMW) regime, isexpected toprovide Ti/Pt/Au metal isdeposited fortheSchottky contact, andthe benefits suchashigher available bandwidth, reduced radar device ispassivated with150A SiN.A cross-sectional SEM aperture andinstrument size, andnarrowed beamwidths for imageisshowninFigure 2,inwhichthetriangle onthe radar andremotesensing applications. Theseapplicationsbottom ofthegateisTimetal. Asaresult ofthegatesize havecalled foreverhigher requirements onthedevice high reduction, thegate-source capacitance, oneofthekey frequency capabilities. Thestate oftheartmmW components parameters thatlimits thehighfrequency performance, is employing short gates between 50-70nmandhighindium reduced byover300O from0.6pF/mmto0.4pF/mm, based on composition channels operating inG-bandfrequencies (140- oursemi-empirical modelextraction fromthemeasured s220GHz)havealready beenreported [1][2]. Thispaper parameters. describes thelatest advancements ofInGaAs/InAlAs/InP High Electron Mobility Transistor (InPHEMT)MMIC technology with35nmprocess that haveenabled thedemonstration of 35nmGate amplification gain above 220GHztoashigh as300GHz.

[1]  A. Tessmann,et al.  220-GHz metamorphic HEMT amplifier MMICs for high-resolution imaging applications , 2005, IEEE Journal of Solid-State Circuits.

[2]  M. Barsky,et al.  InP HEMT amplifier development for G-band (140-220 GHz) applications , 2000, International Electron Devices Meeting 2000. Technical Digest. IEDM (Cat. No.00CH37138).