共查询到20条相似文献,搜索用时 15 毫秒
1.
Ng G.I. Pavlidis D. Tutt M. Oh J.-E. Bhattacharya P.K. 《Electron Device Letters, IEEE》1989,10(3):114-116
The DC and microwave properties of strained In0.65Ga 0.35As/In052Al0.48As HEMTs (high electron-mobility transistors) with double-heterojunction design are presented. The high sheet carrier density and good carrier confinement give rise to excellent device performance with very low output conductance. For 1×150-μm2 long-gate HEMTs, the measured cutoff frequency f T and maximum frequency of oscillation f max are as high as 37 and 66 GHz, respectively 相似文献
2.
Nguyen L.D. Radulescu D.C. Tasker P.J. Schaff W.J. Eastman L.F. 《Electron Device Letters, IEEE》1988,9(8):374-376
The authors report the DC and RF performance of nominally 0.2-μm-gate length atomic-planar doped pseudomorphic Al0.3Ga0.7As/In0.25Ga0.75As modulation-doped field-effect transistors (MODFETs) with f T over 120 GHz. The devices exhibit a maximum two-dimensional electron gas (2 DEG) sheet density of 2.4×1012 cm-2, peak transconductance g m of 530-570 mS/mm. maximum current density of 500-550 mA/mm, and peak current-gain cutoff frequency f T of 110-122 GHz. These results are claimed to be among the best ever reported for pseudomorphic AlGaAs/InGaAs MODFETs and are attributed to the high 2 DEG sheet density, rather than an enhanced saturation velocity, in the In0.25Ga0.75As channel 相似文献
3.
The DC and microwave properties of In0.52Al0.48 Al/InxGa1-xAs (0.53⩽x ⩽0.70) heterostructure insulated gate field-effect transistors (HIGFETs) with a quantum well channel design are presented. DC and microwave transconductances (g m) are enhanced as the In content is increased in the InGaAs channel. An intrinsic microwave g m value of 428 mS/mm and a K -factor of 1140 mS/mm-V have been obtained for 1.0-μm gate length with the 65% In channel devices. The sheet charge density, drift mobility, transconductance, current-gain cutoff frequency (f T), and maximum oscillation frequency (f max) all show a continuous improvement up to 65% In content ( f T=22.5 GHz with 53% and f T=27 GHz with 65% In; the corresponding f max change is from 6.5 to 8 GHz). The device performance degrades as the In content is increased to 70%. DC and microwave characteristics show the presence of negative differential resistance (NDR) up to 2.7 GHz 相似文献
4.
Hong W.P. Bhat R. Nguyen C. Koza M. Caneau C. Chang G.K. 《Electron Devices, IEEE Transactions on》1992,39(12):2817-2818
The authors report the first demonstration of In0.52Al 0.48As/In0.53Ga0.47As metal-semiconductor-metal (MSM) photodetectors and high-electron-mobility transistors (HEMTs) grown on GaAs substrates by organometallic chemical vapor deposition. Both photodetectors and transistors showed no degradation in performance compared to devices simultaneously grown on InP substrates. The photodetectors exhibited a responsivity of 0.45 A/W and leakage current of 10 to 50 nA. The HEMTs with a gate length of 1.0 μm showed a transconductance as high as 250 mS/mm, and f T and f max of 25 and 70 GHz, respectively 相似文献
5.
Greenberg D.R. del Alamo J.A. Harbison J.P. Florez L.T. 《Electron Device Letters, IEEE》1991,12(8):436-438
Molecular beam epitaxy (MBE)-grown L g=1.7-μm pseudomorphic Al0.38Ga0.62As/n+-In0.15Ga 0.85As metal-insulator-doped channel FETs (MIDFETs) are presented that display extremely broad plateaus in both f T and f max versus V GS, with f T sustaining 90% of its peak over a gate swing of 2.6 V. Drain current is highly linear with V GS over this swing, reaching 514 mA/mm. No frequency dispersion in g m up to 3 GHz was found, indicating the absence of electrically active traps in the undoped AlGaAs pseudoinsulator layer. These properties combine to make the pseudomorphic MIDFET highly suited to linear, large-signal, broadband applications 相似文献
6.
Aina L. Burgess M. Mattingly M. O'Connor J.M. Meerschaert A. Tong M. Ketterson A. Adesida I. 《Electron Device Letters, IEEE》1991,12(9):483-485
The fabrication of 0.33-μm gate-length AlInAs/InP high electron mobility transistors (HEMTs) is reported. These InP-channel devices have f t values as high as 76 GHz, f max values of 146 GHz, and maximum stable gains of 16.8, 14, and 12 dB at 10, 18, and 30 GHz, respectively. The extrinsic DC transconductances are as high as 610 mS/mm; with drain-source breakdown voltages exceeding 10 V. The effective electron velocity in the InP channel is estimated to be at least 1.8×107 cm/s, while the f tL g product is 29 GHz-μm. These results are comparable to the best reported results for similar InGaAs-channel devices 相似文献
7.
AlGaAs/GaAs collector-up heterojunction bipolar transistors (HBTs) with a heavily carbon-doped base layer were fabricated using oxygen-ion implantation and zinc diffusion. The high resistivity of the oxygen-ion-implanted AlGaAs layer in the external emitter region effectively suppressed electron injection from the emitter, allowing collector current densities to reach values above 105 A/cm 2. For a transistor with a 2-μm×10-μm collector, f T was 70 GHz and f max was as high as 128 GHz. It was demonstrated by on-wafer measurements that the first power performance of collector-up HBTs resulted in a maximum power-added efficiency of as high as 63.4% at 3 GHz 相似文献
8.
The usual approximate expression for measured f T =[g m/2π (C gs+C gd)] is inadequate. At low drain voltages just beyond the knee of the DC I -V curves, where intrinsic f t is a maximum for millimeter-wave MODFETs, the high values of C gd and G ds combine with the high g m to make terms involving the source and drain resistance significant. It is shown that these resistances can degrade the measured f T of a 0.30-μm GaAs-AlGaAs MODFET from an intrinsic maximum f T value of 73 GHz to a measured maximum value of 59 GHz. The correct extraction of maximum f T is essential for determining electron velocity and optimizing low-noise performance 相似文献
9.
Yan R.-H. Lee K.F. Jeon D.Y. Kim Y.O. Park B.G. Pinto M.R. Rafferty C.S. Tennant D.M. Westerwick E.H. Chin G.M. Morris M.D. Early K. Mulgrew P. Mansfield W.M. Watts R.K. Voshchenkov A.M. Bokor J. Swartz R.G. Ourmazd A. 《Electron Device Letters, IEEE》1992,13(5):256-258
The authors report the implementation of deep-submicrometer Si MOSFETs that at room temperature have a unity-current-gain cutoff frequency (f T) of 89 GHz, for a drain-to-source bias of 1.5 V, a gate-to-source bias of 1 V, a gate oxide thickness of 40 Å, and a channel length of 0.15 μm. The fabrication procedure is mostly conventional, except for the e-beam defined gates. The speed performance is achieved through an intrinsic transit time of only 1.8 ps across the active device region 相似文献
10.
Schmitz A.E. Walden R.H. Larson L.E. Rosenbaum S.E. Metzger R.A. Behnke J.R. Macdonald P.A. 《Electron Device Letters, IEEE》1991,12(1):16-17
0.35-μm complementary metal-oxide-semiconductor (CMOS)/silicon-on-sapphire (SOS) n- and p-channel MOSFETs with a metal-over-polysilicon T-gate structure for monolithic microwave integrated circuit (MMIC) and digital applications are reported. The measured values for the current-gain cutoff frequency f T were ⩾20 GHz for both n-channel and p-channel devices, and the values for the unilateral power-gain cutoff frequency f max were 37 GHz for the p-channel and 53 GHz for the n-channel MOSFETs. The low effective resistance of the T-gate structure contributed to the very high f max values. It is believed that these are the highest f T and f max values ever reported for MOS devices. The potential of SOS submicrometer MOSFETs for microwave circuit applications is demonstrated 相似文献
11.
《Electron Devices, IEEE Transactions on》1990,37(1):153-158
The fabrication of a silicon heterojunction microwave bipolar transistor with an n+ a-Si:H emitter is discussed, and experimental results are given. The device provides a base sheet resistance of 2 kΩ/□ a base width 0.1 μm, a maximum current gain of 21 (V CE=6 V, I c=15 mA), and an emitter Gummel number G E of about 1.4×1014 Scm-4. From the measured S parameters, a cutoff frequency f t of 5.5 GHz and maximum oscillating frequency f max of 7.5 GHz at V CE=10 V, I c=10 mA are obtained 相似文献
12.
An attempt is made to reconcile the various approaches that have recently been used to estimate the maximum frequency of oscillation f max in high-performance AlGaAs/GaAs HBTs. f max is computed numerically from the full expression for Mason's invariant gain using y -parameters derived from the different approaches, i.e., the hybrid-π equivalent circuit, the T-equivalent circuit, and the drift-diffusion equations. It is shown that the results for f max are essentially the same, irrespective of the source of the y -parameters, provided that the phase delays due to transit of carriers across the base and the collector-base depletion region are properly accounted for. It is also shown, for the particular device studied, that the widely used analytical expression for f max, involving f T and effective base resistance and collector capacitance, is remarkably accurate for frequencies below those at which transit-time effects become important 相似文献
13.
Patton G.L. Comfort J.H. Meyerson B.S. Crabbe E.F. Scilla G.J. de Fresart E. Stork J.M.C. Sun J.Y.-C. Harame D.L. Burghartz J.N. 《Electron Device Letters, IEEE》1990,11(4):171-173
The fabrication of silicon heterojunction bipolar transistors which have a record unity-current-gain cutoff frequency (f T) of 75 GHz for a collector-base bias of 1 V, an intrinsic base sheet resistance (R bi) of 17 kΩ/□, and an emitter width of 0.9 μm is discussed. This performance level, which represents an increase by almost a factor of 2 in the speed of a Si bipolar transistor, was achieved in a poly-emitter bipolar process by using SiGe for the base material. The germanium was graded in the 45-nm base to create a drift field of approximately 20 kV/cm, resulting in an intrinsic transit time of only 1.9 ps 相似文献
14.
Lai R. Bhattacharya P.K. Alterovitz S.A. Downey A.N. Chorey C. 《Electron Device Letters, IEEE》1990,11(12):564-566
Low-temperature microwave measurements of both lattice-matched and pseudomorphic InxGa1-xAs/In0.48As (x =0.53, 0.60, and 0.70) channel MODFETs on InP substrates were carried out in a cryogenic measurement system. The measurements were done in the temperature range of 77 to 300 K and in the frequency range of 0.5 to 11.0 GHz at different bias conditions. The cutoff frequency ( f T) for the InxGa1-xAs/In0.52Al0.48As MODFETs improved from 22 to 29 GHz, 29 to 38 GHz, and 39 to 51 GHz, for x =0.53, 0.60, and 0.70, respectively, as the temperature was lowered from 300 to 77 K, which is approximately a 31% increase at each composition. No degradations were observed in device performance. These results indicate an excellent potential of the pseudomorphic devices at low temperatures 相似文献
15.
Chao P.C. Tessmer A.J. Duh K.-H.G. Ho P. Kao M.-Y. Smith P.M. Ballingall J.M. Liu S.-M.J. Jabra A.A. 《Electron Device Letters, IEEE》1990,11(1):59-62
Very low-noise 0.15-μm gate-length W -band In0.52 Al0.48As/In0.53Ga0.47As/In 0.52Al0.48As/InP lattice-matched HEMTs are discussed. A maximum extrinsic transconductance of 1300 mS/mm has been measured for the device. At 18 GHz, a noise figure of 0.3 dB with an associated gain of 17.2 dB was measured. The device also exhibited a minimum noise figure of 1.4 dB with 6.6-dB associated gain at 93 GHz. A maximum available gain of 12.6 dB at 95 GHz, corresponding to a maximum frequency of oscillation, f max, of 405 GHz (-6-dB/octave extrapolation) in the device was measured. These are the best device results yet reported. These results clearly demonstrate the potential of the InP-based HEMTs for low-noise applications, at least up to 100 GHz 相似文献
16.
Ng G.-I. Pavlidis D. Jaffe M. Singh J. Chau H.-F. 《Electron Devices, IEEE Transactions on》1989,36(10):2249-2259
Strained In0.52Al0.48 As/InxGa 1-xAs (x >0.53) HEMTs (high electron mobility transistors) are studied theoretically and experimentally. A device design procedure is reported that is based on band structure and charge control self-consistent calculations. It predicts the sheet carrier density and electron confinement as a function of doping and thickness of layers. The DC performance at 300 K is presented. Wafer statistics demonstrate improvement of device characteristics with excess indium in the channel (g¯m, intr=500 and 700 mS/mm for x=0.60 and 0.65). Microwave characterization shows the f T improvement (f T=40 and 45 GHz for x =0.60 and 0.65, respectively) and the R ds limitations of the 1-μm-long-gate HEMTs 相似文献
17.
The fabrication and characterization of a 0.25-μm-gate, ion-implanted GaAs MESFET with a maximum current-gain cutoff frequency f t of 126 GHz is reported. Extrapolation of current gains from bias-dependent S -parameters at 70-100% of I dss yields f 1's of 108-126 GHz. It is projected that an f 1 of 320 GHz is achievable with 0.1-μm-gate GaAs MESFETs. This demonstration of f 1's over 100 GHz with practical 0.25-μm gate length substantially advances the high-frequency operation limits of short-gate GaAs MESFETs 相似文献
18.
Li W.Q. Karakucuk M. Freeman P.N. East J.R. Haddad G.I. Bhattacharya P.K. 《Electron Device Letters, IEEE》1993,14(7):335-337
The authors have measured the high-frequency characteristics and temporal response of a GaAs/AlGaAs heterojunction phototransistor with a GaAs/Al0.2Ga0.8 multi-quantum-well collector. The quantum wells offer tunability of the photoresponse (10 nm for a bias change of 4 V) and a negative differential resistance in the photocurrent-voltage characteristics. Measured values of f T and f max are 20 and 6 GHz, respectively. The temporal response to short-pulse optical excitation is characterized by a linewidth of 46 ps. Such devices are attractive candidates for making optically induced oscillators 相似文献
19.
An In0.41Al0.59As/n+-In0.65 Ga0.35As HFET on InP was designed and fabricated, using the following methodology to enhance device breakdown: a quantum-well channel to introduce electron quantization and increase the effective channel bandgap, a strained In0.41Al0.59As insulator, and the elimination of parasitic mesa-sidewall gate leakage. The In0.65Ga0.35As channel is optimally doped to N D=6×1018 cm-3. The resulting device (L g=1.9 μm, W g =200 μm) has f t=14.9 GHz, f max in the range of 85 to 101 GHz, MSG=17.6 dB at 12 GHz V B=12.8 V, and I D(max)=302 mA/mm. This structure offers the promise of high-voltage applications at high frequencies on InP 相似文献
20.
Chough K.B. Chang T.Y. Feuer M.D. Sauer N.J. Lalevic B. 《Electron Device Letters, IEEE》1992,13(9):451-453
Record high f TL g products of 57 and 46 GHz-μm have been achieved in Ga1-x Inx As/AlInAs MODFETs with a strain compensated channel of x =0.77 and a lattice-matched channel of x =0.53, respectively. Although gm as high as 950 mS/mm has been obtained by conventional deep recess for the gate, these latter devices show a prominent kink effect which lowers f T and the voltage gain. By limiting the depth of final nonselective recess etch to 3 nm with the help of selective step etches, f T as high as 47 GHz and gm as high as 843 mS/mm have been achieved for MODFETs with x =0.77 and L g=1.1 μm 相似文献