共查询到20条相似文献,搜索用时 31 毫秒
1.
《Electron Device Letters, IEEE》1986,7(5):320-323
The successful application of short-term halogen lamp annealing to form ohmic contacts to AlGaAs/GaAs and In0.52 Al0.48 As/ In0.53 Ga0.47 As modulation-doped structures is demonstrated. Use of Ti in the electron-beam evaporated metallization scheme and a two-step annealing cycle give contacts with reproducibly good electrical and morphological characteristics. Minimum values of specific contact resistancerho_{c} = 4.0 times 10^{-7} and6.0 times 10^{-7} Ω.cm2for AlGaAs/GaAs and In0.52 Al0.48 As/In0.53 Ga0.47 As, respectively, are measured. Corresponding values of the transfer resistance Rc are 0.12 ± 0.02 and 0.18 ± 0.05 Ω.mm. These values are the lowest achieved with lamp annealing and are comparable to the best obtained with transient furnace annealing. 相似文献
2.
《Electron Device Letters, IEEE》1985,6(12):642-644
This letter reports the materials characteristics and device performance of a In0.53 Ga0.47 As-In0.52 Al0.48 As single quantum well (SQW) field-effect transistor grown by molecular beam epitaxy on 相似文献
3.
《Electron Device Letters, IEEE》1987,8(12):579-581
High-speed In0.53 Ga0.47 As/In0.52 Al0.48 As photodiodes have been grown by molecular beam epitaxy (MBE) on semi-insulating InP substrates and fabricated. The measured impulse response characteristics are very close to the analytically calculated ones. The temporal response to pulsed optical excitation is characterized by a rise time of 21 ps and a width (FWHM) of 27 ps. The 25 × 20-µm2diodes have a junction capacitance <0.1 pF, a dark current ∼1 nA, and a peak responsivity of 0.35 A/W. These characteristics are comparable or better than most epitaxial InGaAs photodiodes reported to date and make the devices suitable for a host of high-speed applications and monolithic integration. 相似文献
4.
《Electron Device Letters, IEEE》1987,8(11):534-536
An In0.52 Al0.48 As/n+-In0.53 Ga0.47 As MIS-type field-effect transistor (FET) with a channel doped at a 7 × 1017cm-3level has been fabricated on an InP substrate. A device with a 2-µm channel length has yielded a maximum transconductance of 152 mS/mm,f_{T} = 12.4 GHz, andf_{max} = 50 GHz. At 10 GHz, the maximum available gain is 17.4 dB. The performance of this device shows that heavily doped channel FET's are very promising for high-frequency operation. 相似文献
5.
《Electron Device Letters, IEEE》1986,7(8):480-482
A new model for interface roughness scattering in modulation-doped (MD) heterostructures, based on the physical structure of a molecular beam epitaxy- (MBE) grown heterointerface, is formulated. The parameters describing interface roughness have been derived from growth studies and analysis of photoluminescence linewidths of quantum wells. The model has been applied to analyze low-temperature electron mobilities in normal and inverted In0.53 Ga0.47 As-In0.52 Al0.48 As MD heterostructures. It is found that the mobility in the normal heterostructure is limited by alloy scattering, whereas both alloy and interface roughness scattering play equally dominant roles in the inverted structure. 相似文献
6.
《Electron Devices, IEEE Transactions on》1987,34(2):235-240
The effects of pulsed halogen-lamp annealing on modulation-doped In0.53 Ga0.47 As/In0.52 Al0.48 As heterostructures and Si-implanted In0.53 Ga0.47 As have been studied to determine the suitabiiity of this process in the fabrication of high-performance field-effect transistors. Implantation and annealing of these materials are necessary for contact and self-aligned gate formation. Mobilities as high as 7400 cm2/ V . s are measured at 300 K in undoped molecular-beam epitaxy In-GaAs implanted with 8 × 1012cm-2 29Si+and lamp annealed at 700°C for 5 s. Anomalous overactivations (up to 120 percent) are observed in these layers When silox encapsulation is used during annealing, but the effect is absent for GaAs proximity capping. Sharp decreases in sheet-electron concentration and mobility occur in the normal modulation-doped structures for annealing temperatures > 750°C, while this trend is much smaller in the inverted structures. Arsenic loss from the In-AlAs doping layer is attributed as the main mechanism for this behavior, which makes the inverted structure more suitable for device processing. Depth profiling in the modulation-doped structures indicates that there may be serious pinchoff problems in these devices when annealed at higher temperatures due to outdiffusion of impurities from the InP substrate. Values of interdiffusion coefficients at the InGaAs/ InAIAs heterointerfaces, being reported for the first time, are almost three orders higher than those measured in the GaAs/AIAs systems. 相似文献
7.
《Electron Device Letters, IEEE》1986,7(7):436-439
In this letter we examine theoretically the potential of an In0.52 Al0.48 As/In0.53 Ga0.47 As modulation-doped field-effect transistor in which the usual InGaAs channel is replaced by an (InAs)m (GaAs)m superlattice with m ≲ 4, extending over 100 ∼ 200 Å from the InAlAs interface. For small m the superlattice bandstructure is essentially the same as that of the alloy and the effects of the very small lattice mismatch are negligible. More importantly, the electrons in the active channel are not expected to suffer any alloy scattering since the channel now has perfect long-range order with no random potential fluctuations. We show that this MODFET has extremely high mobility and its low-temperature mobility can be an order of magnitude higher than that of the conventional InAlAs/InGaAs MODFET. Comparison is also made with the AlGaAs/GaAs MODFET and results indicate that the proposed structure has superior potential performance. 相似文献
8.
《Electron Device Letters, IEEE》1985,6(7):384-386
Depletion-mode junction field-effect transistors (JFET's) with InGaAs p-n junctions grown on compensated Fe:InP or highly resistive In0.52 Al0.48 As isolation layers grown on n+-InP substrates have been fabricated using a combination of molecular-beam epitaxy and metalorganic chemical vapor deposition growth techniques. Using a self-aligned gate technology with a 1-µm gate length, devices with high transconductance (80 mS/mm), low leakage current (<100 nA), and a gate-to-source capacitance of 0.4 pF have been fabricated. This is apparently the first report where InP-based alloy FET's have been fabricated on an isolated n+-substrate. This structure has application to monolithically integrated photoreceivers. 相似文献
9.
《Electron Device Letters, IEEE》1983,4(10):383-385
We report the first vertical n-p-n heterojunction bipolar transistors formed in the (Al,In)As/(Ga,In)As alloy system. The structures grown by molecular-beam epitaxy (MBE) use a wide band-gap (Eg = 1.44 eV) Al0.48 In0.52 As emitter on a lower band gap (Eg = 0.73 eV) Ga0.47 In0.53 As base 2500 Å in width. Transistors with both abrupt and graded heterojunction emitters were demonstrated with dc current gains of 140 and 280, respectively, at a collector current of 15 mA. The (Al,In)As/(Ga,In)As heterojunction transistors offer the attractive possibility of optical integration with long wavelength lasers and photodetectors. 相似文献
10.
《Electron Device Letters, IEEE》1987,8(5):217-219
Deep O+ implantation has been used to create a high-resistivity layer buried beneath the Be+ -implanted extrinsic base-emitter junction region of In0.52 Al0.48 As/In0.53 Ga0.47 As inverted (emitter-down) heterojunction bipolar transistors (HBT's). The O+ -implanted layer remains highly resistive even after a rapid thermal annealing step at 700°C to activate the Be+ implants. With the O+ implantation, the forward current of the extrinsic base-emitter diode is significantly reduced. HBT's with Be+ - and O+ -implanted extrinsic base regions exhibit current gains of ≃ 100 at a collector current density in excess of 103A/cm2. Another benefit from the deep O+ -implanted layer is a dramatic reduction in the junction capacitance of the extrinsic base-emitter diode. 相似文献
11.
《Electron Device Letters, IEEE》1982,3(3):64-66
Schottky-gate FET's have been fabricated on n-type In0.53 Ga0.47 As using a thin interfacial silicon nitride layer between the metal and the epitaxial layer to reduce the gate leakage current. In0.53 Ga0.47 As was grown by molecular beam epitaxy on semi-insulating InP substrates and silicon nitride was grown by plasma-enhanced chemical vapor deposition. Devices with 1.2µm gate length and net donor doping in the mid 1016cm-3range show dc transconductance of up to 130mS/mm. Both depletion and enhancement mode operation were observed. The effective saturation velocity of electrons in the channel is deduced to be 2.0 ± 0.5 × 107cm/sec, a value 60 to 70% higher than that in GaAs MESFET's. The insulator-assisted gate technology has many advantages in fabrication flexibility and control compared with other approaches to realizing high-speed microwave and logic in FET's in In0.53 Ga0.47 As. 相似文献
12.
《Electron Device Letters, IEEE》1982,3(8):205-208
We report a selectively doped Ga0.47 In0.53 As/Al0.48 In0.52 As field effect transistor with a 1.2 µm gate length and present a model of two-region operation to analyze its I-V characteristics. This depletion mode transistor shows complete pinch-off and saturation characteristics with a low frequency transconductance of 70 mmho/ mm at 300 K and 125 mmho/mm at 77 K. The theoretical model, which includes the background carriers in the undoped Ga0.47 In0.52 As layer, agrees with the experimental results. 相似文献
13.
《Electron Device Letters, IEEE》1985,6(10):491-493
This letter describes high electron mobility transistors (HEMT's) utilizing a conducting channel which is a single In0.15 Ga0.85 AS quantum well grown pseudomorphically on a GaAs substrate. A Hall mobility of 40 000 cm2/V.s has been observed at 77 K. Shubnikov-de Haas oscillations have been observed at 4.2 K which verify the existence of a two-dimensional electron gas at the In0.15 Ga0.85 As/GaAs interface. HEMT's fabricated with 2-µm gate lengths show an extrinsic transconductance of 90 and 140 mS/mm at 300 and 77 K, respectively-significantly larger than that previously reported for strained-layer superlattice Inx Ga1-x As structures which are nonpseudomorphic to GaAs substrates. HEMT's with 1-µm gate lengths have been fabricated, which show an extrinsic transconductance of 175 mS/mm at 300 K which is higher than previously reported values for both strained and unstrained Inx Ga1-x As FET's. The absence of Alx Ga1-x As in these structures has eliminated both the persistent photoconductivity effect and drain current collapse at 77 K. 相似文献
14.
《Electron Device Letters, IEEE》1987,8(1):33-35
We have successfully fabricated FET's with In0.53 Ga0.47 As channels, lattice-matched In0.52 Al0.48 As gate barriers, and n+ In0.53 - Ga0.47 As gates. For a barrier thickness of 600 Å and a gate length of 1.7 µm, the maximum transconductance is 250 mS/mm at T = 300 K. From gate capacitance measurements, the cutoff frequency is inferred to be ft = 15 GHz for this gate length. Self-aligned source and drain implants have been used to permit nonalloyed ohmic contacts with a characteristic resistance of 0.1 Ω.mm. The transconductance remains above 210 mS/mm for forward gate bias up to +1.0 V, confirming the usefulness of this gate structure for enhancement-mode devices. 相似文献
15.
We calculate operating characteristics of high-sensitivity high-speed In0.53 Ga0.47 As/InP avalanche photodiodes (APD's). We find that significant photocurrent gain is obtained for a total fixed-charge density ofsigma_{tot} > 3 times 10^{12} cm-2in the depleted InP and0.53 Ga0.47 As regions. To obtain high quantum efficiency and low tunneling currents, the fixed-charge density in the InP must be in the range2 times 10^{12} cm-2leq sigma_{B} leq 3 times 10^{12} cm-2. We calculate the breakdown voltages for APD's with uniformly doped layers and find that practical detectors with avalanche breakdowns as low as 15 V can be realized. High quantum efficiency and fast response are obtained by compositional grading of the In0.53 Ga0.47 As heterointerface over a distance ofL gsim 380 Å, depending on the doping and amount of the In0.53 Ga0.47 As layer swept out at breakdown. Finally, a comparison of calculations with experimental results is presented. 相似文献
16.
《Electron Devices, IEEE Transactions on》1986,33(1):67-71
Photoconductive detectors were fabricated on In0.53 - Ga0.47 As/InP made high-resistive by doping with elemental Fe. A mobility of ∼ 6000 cm2/V . s and a net electron concentration of (2-5) × 1012cm-3were measured in layers on which the devices were fabricated. Photoconductive gains of 5-10 were measured with CW and pulsed excitation. The calculation response time to 300-ps pulsed excitation is ∼ 100 ps and can be improved with reduced channel spacings. Typical dark currents in the devices are of the order of 50 µ A at room temperature. The noise power into a 50-Ω load measured at 82°C is -108.9 dBm. This is the lowest value measured in photoconductive detectors made with III-V In0.53 Ga0.47 As. 相似文献
17.
《Electron Device Letters, IEEE》1980,1(6):110-111
Preliminary results are reported for the operation of a junction field-effect transistor fabricated from In0.53 Ga0.47 As grown lattice-matched to an InP:Fe substrate. 相似文献
18.
《Electron Device Letters, IEEE》1987,8(9):380-382
High-performance pseudomorphic Ga0.4 In0.6 As/ Al0.55 In0.45 As modulation-doped field-effect transistors (MODFET's) grown by MBE on InP have been fabricated and characterized. DC transconductances as high as 271, 227, and 197 mS/mm were obtained at 300K for 1.6-µm and 2.9-µm gate-length enhancement-mode and 2-µm depletion-mode devices, respectively. An average electron velocity as high as 2.36 × 107cm/s has been inferred for the 1.6-µm devices, which is higher than previously reported values for 1-µm gate-length Ga0.47 In0.53 As/Al0.48 In0.52 As MODFET's. The higher bandgap Al0.55 In0.45 As pseudomorphic barrier also offers the advantages of a larger conduction-band discontinuity and a higher Schottky barrier height. 相似文献
19.
《Electron Device Letters, IEEE》1981,2(11):288-290
We describe the operation of an n-channel inversion-mode In0.53 Ga0.47 As MISFET with a Si3 N4 insulating layer. This device exhibits a transconductance of 2 mS/mm, which represents an order of magnitude improvement over previously reported In0.53 Ga0.47 As MISFET results. 相似文献
20.
《Electron Device Letters, IEEE》1980,1(4):55-57
A punch-through type planar photodiode with low dark current and high speed response was fabricated from low carrier density In0.53 Ga0.47 As grown by vapor-phase epitaxy. Dark current density was 3.1 × 10-5A/cm2at 10 V bias. Rise time and full width at half maximum were 82 and 126 psec, respectively, at a bias above 4 V. 相似文献