The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Modulation-doped GaAs/In0.25Ga0.75As/Al0.3Ga0.7 As HEMT structures were grown using different MBE-growth temperatures and In0.25Ga0.75As channel thicknesses. Drain current DLTS measurements performed on these samples using a Fourier-Transform technique show that the concentrations of both bulk and interface traps depend greatly on growth temperature. In addition, a broadening of one of the DLTS peaks...
We show that a remarkable threshold shift ??Vp and an increase in the saturation current ??Ids can be observed in AlGaAs/InGaAs PM-HEMT's submitted to high temperature (100??C - 200 ??C) storage or hot-electron stresses for relatively short times (about 20 hours). An increase in Ids up to 40% has been observed. The increase is not permanent and can be recovered by a room or low temperature storage...
A new GaInP-GaAs HBT technology is proposed in which a thin GaInP layer (40 nm) is used both as the emitter and as a passivation layer of the base. High DC current gain up to 40 are obtained, for a high C doping level (6 1019 cm??3) in the base. The GaInP passivation is demonstrated with the achievement of the same DC current gain for small and large devices with emitter-base junction area of 16 to...
A lattice-matched In0.53Al0.22Ga0.25 As/InP heterojunction bipolar transistor has been fabricated successfully by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) for the first time. This structure reveals a current gain of 85 at a collector density of 145 A/cm2, along with an offset voltage as low as 50 mV. No potential spike due to zero conduction band discontinuity at the emitter-base...
The current dependence of small signal base-collector capacitance, Cbc and base series resistance, Rb, extracted directly from S-parameters, has been investigated in microwave n-p-n AlGaAs/GaAs HBTs. It is found that the magnitude of Cbc at Vce=3V in our devices is relatively constant at low current densities but reduces at current density of 2??103A/cm2 and then increases rapidly at a critical value...
We present experimental results of hot electron noise in Si doped n+nn+ AlxGa1-xAs structures with x=0.15, 0.2 and 0.25 using H.F.pulsed noise measurements. Noise temperature and longitudinal diffusion coefficient as functions of field strength are compared with Si doped GaAs data. Results are discussed from the point of view of electron scattering mechanisms. The possibility of self-heating effects...
This work introduces a comprehensive analytic model of the sputtering mechanism present in IBE and RIE processes. Our final objective is to correlate the etch rate to the plasma reactor parameters. Experimental verifications for GaAs etching show a good agreement for IBE. In the case of RIE, the non perfect agreement is explained by the influence of effects such as flow rate and temperature not taken...
This paper presents a characterization of the main transient phenomena affecting the S-parameters of GaAs MESFETs, carried out by means of an innovative Six Port Network Analyzer operated in burst mode. The results, interpreted using established models of the small signal MESFET behavior, indicate that the transient effects observed in the S-parameters must be attributed to changes in the device transconductance...
Double quantum well with ??doped lattice-strain GaAs/InGaAs/GaAs pseudomorphic heterostructures have been fabricated for the first time. Very high carrier density of more than 1??1013cm??2 along with enhanced mobility of 2100 cm2/vs at 300K are achieved. Influence of barrier thickness on the carrier densities and mobilities are also investigated.
A vertical GaAs FET with sub-??m gate length has been grown using selective epitaxy. The gate structure of this device consists of an insulator/metal/insulator multilayer. The advantage of this structure is the reduction of the gate-source and gate-drain capacitances due to the relatively low dielectric constant of the insulator. In addition the insulator above the metal gate enables to use the selective...
We report a study of threshold and output power behavior of vertical-cavity surface-emitting laser diodes with respect to the offset between spectral gain and mode position which is of great interest for the design of this laser devices. For an optimal adjustment of gain peak and mirror reflectivity we obtained a minimum threshold current density of less than 400 A/cm2, which is to our knowledge the...
We report recent results obtained on GaLaP/GaAs heterojunction bipolar transistors. A small-signal and noise model is used to investigate RF and noise characteristics.
This paper describes a self-aligned AlGaAs/GaAs heterojunction bipolar transistor technology using selective chemical beam epitaxy. The process is achieved by a selective regrowth of the extrinsic base layer. Digital circuits and laser drivers operating at 10 Gb/s have been successfully demonstrated for the first time with this process.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.