The role of inefficient charge modulations in limiting the current-gain cutoff frequency of the MODFET

1988 ◽  
Vol 35 (7) ◽  
pp. 871-878 ◽  
Author(s):  
M.C. Foisy ◽  
P.J. Tasker ◽  
B. Hughes ◽  
L.F. Eastman
Keyword(s):  
Cutoff Frequency ◽  
Current Gain ◽  
Charge Modulations

High Breakdown Voltage GaN HEMT Device Fabricated on Self-Standing GaN Substrate

2013 ◽  
Vol 347-350 ◽  
pp. 1535-1539
Author(s):  
Jian Jun Zhou ◽  
Liang Li ◽  
Hai Yan Lu ◽  
Ceng Kong ◽  
Yue Chan Kong ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Breakdown Voltage ◽  
Oxygen Plasma ◽  
Cutoff Frequency ◽  
Chemical Vapor ◽  
Current Gain ◽  
Organic Chemical ◽  
Oxygen Plasma Treatment ◽  
Gan Hemt ◽  
High Breakdown Voltage

In this letter, a high breakdown voltage GaN HEMT device fabricated on semi-insulating self-standing GaN substrate is presented. High quality AlGaN/GaN epilayer was grown on self-standing GaN substrate by metal organic chemical vapor deposition. A 0.8μm gate length GaN HEMT device was fabricated with oxygen plasma treatment. By using oxygen plasma treatment, gate forward working voltage is increased, and a breakdown voltage of more than 170V is demonstrated. The measured maximum drain current of the device is larger than 700 mA/mm at 4V gate bias voltage. The maximum transconductance of the device is 162 mS/mm. In addition, high frequency performance of the GaN HEMT device is also obtained. The current gain cutoff frequency and power gain cutoff frequency are 19.7 GHz and 32.8 GHz, respectively. A high fT-LG product of 15.76 GHzμm indicating that homoepitaxy technology is helpful to improve the frequency performance of the device.

VERTICAL SCALING OF TYPE I InP HBT WITH FT > 500 GHZ

2004 ◽  
Vol 14 (03) ◽  
pp. 625-631 ◽  
Author(s):  
J. W. LAI ◽  
W. HAFEZ ◽  
M. FENG
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Impact Ionization ◽  
Cutoff Frequency ◽  
Current Gain ◽  
Vertical Scaling ◽  
Physical Parameters ◽  
Type I ◽  
Peak Current Density ◽  
Rf Performance

We have fabricated the high-speed InP/InGaAs -based single heterojunction bipolar transistors (SHBTs) with current gain cutoff frequency, fT from 166GHz to over 500GHz by the approach of vertical scaling. Collector thickness is reduced from 3000Å to 750Å and the peak current density is increased up to 1300kA/cm2. In this paper, device rf performance has been compared with respect to materials with different vertical dimensions. The scaling limitation is also studied by analytical approach. The extracted physical parameters suggest that the parasitic emitter resistance is the major limit on further enhancing ultra-scaled HBT intrinsic speed due to the associated RECBC delay. The cut-off frequency of a 500Å collector SHBT has been measured and the results indicate a dramatic drop on fT, supporting the conclusion projected by model analysis. It is also commented that for deeply downscaled HBTs, impact ionization could be another degrading mechanism limits device bandwidth.

1510 mS/mm 0.1 [micro sign]m gate length pseudomorphic HEMTs with intrinsic current gain cutoff frequency of 220 GHz

1996 ◽  
Vol 32 (9) ◽  
pp. 848 ◽  
Author(s):  
F. Diette ◽  
D. Langrez ◽  
J.L. Codron ◽  
E. Delos ◽  
D. Theron ◽  
...  
Keyword(s):  
Cutoff Frequency ◽  
Current Gain ◽  
Gate Length

Role of a-Si in Enhancing the Current Gain of Si-based MSM Photodetector using Conventional Method

2011 ◽  
Author(s):  
S. P. Lim ◽  
M. R. Hashim ◽  
Abdul Manaf Hashim ◽  
Vijay K. Arora
Keyword(s):  
Conventional Method ◽  
Current Gain ◽  
Msm Photodetector

Strain-engineering in AlGaN/GaN HEMTs: impact of silicon nitride passivation layer on electrical performance

2021 ◽  
Author(s):  
Sanghamitra Das ◽  
Taraprasanna Dash ◽  
Devika Jena ◽  
Eleena Mohapatra ◽  
C K Maiti
Keyword(s):  
Experimental Data ◽  
Compressive Strain ◽  
Cutoff Frequency ◽  
Strain Engineering ◽  
Electrical Performance ◽  
Current Gain ◽  
Great Promise ◽  
High Electron ◽  
Wide Range ◽  
Gan Hemts

Abstract In this work, we present a physics-based analysis of two-dimensional electron gas (2DEG) sheet carrier density and other microwave characteristics such as transconductance and cutoff frequency of AlxGa1-xN/GaN high electron mobility transistors (HEMT). An accurate polarization-dependent charge control-based analysis is performed for microwave performance assessment in terms of current, transconductance, gate capacitances, and cutoff frequency of lattice-mismatched AlGaN/GaN HEMTs. The influence of stress on spontaneous and piezoelectric polarization is included in the simulation of an AlGaN/GaN HEMT. We have shown the change in threshold voltage (Vt) due to tensile and compressive strain with different gate lengths. Also, the influence of stress due to the change in nitride thickness is presented. Our simulation results for drain current, transconductance, and current-gain cutoff frequency for various gate length devices are calibrated and verified with experimental data over a wide range of gate and drain applied voltages, which are expected to be useful for microwave circuit design. The predicted transconductance, drain conductance, and operation frequency are quite close to the experimental data. The AlGaN/GaN heterostructure HEMTs with nitride passivation layers show great promise as a candidate in future high speed and high power applications.

Effect of GaN Cap Layer on the Electrical Properties of AlGaN/GaN HEMT

2012 ◽  
Vol 217-219 ◽  
pp. 2393-2396 ◽  
Author(s):  
Han Guo ◽  
Wu Tang ◽  
Wei Zhou ◽  
Chi Ming Li
Keyword(s):  
Electrical Properties ◽  
Doping Concentration ◽  
Cutoff Frequency ◽  
High Electron Mobility Transistor ◽  
Current Gain ◽  
High Electron ◽  
Saturation Current ◽  
Gan Hemt ◽  
Cap Layer ◽  
Dimensional Electron Gas

The electrical properties of AlGaN/GaN heterojunction high electron mobility transistor (HEMT) are simulated by using sentaurus software. This paper compares two structures, the HEMT with GaN cap layer and the HEMT without GaN cap layer. The sentaurus software simulates the DC and AC characteristics of the two AlGaN/GaN HEMT structures. The HEMT with GaN cap layer can increase the maximum transconductance gm from 177ms/mm to 399ms/mm when the doping concentration of the cap layer is 3×1018cm-3 compared with the other structure under the same conditions. The simulation results indicate that the HEMT with cap layer can increase maximum transconductance gm, saturation current Ids, current-gain cutoff frequency fT, maximum oscillation frequency fmax and reduce the series resistance of the drain to source compared with the HEMT without GaN cap layer. The large Ids of the HEMT with cap layer is attributed to the increase of the concentration of two dimensional electron gas (2DEG). Moreover, the change of the doping concentration of the cap layer will affect the gm and Ids.

Complex current gain and cutoff frequency determination of HBTs

2000 ◽  
Vol 36 (14) ◽  
pp. 1236 ◽  
Author(s):  
N. Zerounian ◽  
F. Aniel ◽  
R. Adde
Keyword(s):  
Cutoff Frequency ◽  
Current Gain ◽  
Frequency Determination
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