Influence of quantum well width on DC and RF device performance in pseudomorphic Al/sub 0.30/Ga/sub 0.70/As/In/sub 0.25/Ga/sub 0.75/As MODFETs

An experimental study of the influence of quantum well width on DC and RF device performance in nominally 0.2- mu m gate-length atomic-planar doped pseudomorphic Al/sub 0.30/Ga/sub 0.70/As/In/sub 0.25/Ga/sub 0.75/As MODFETs is reported. Three important results have been obtained: (1) a well width of...

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Bibliographic Details
Published inIEEE transactions on electron devices Vol. 35; no. 12; pp. 2451 - 2452
Main Authors Nguyen, L.D., Radulescu, D.C., Tasker, P.J., Foisy, M.C., Eastman, L.F.
Format Journal Article
LanguageEnglish
Published IEEE 01.12.1988
Subjects
Bandwidth
Current density
Cutoff frequency
Distributed parameter circuits
Indium
Performance gain
Radio frequency
Sampling methods
Schottky diodes
Signal generators
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Summary:An experimental study of the influence of quantum well width on DC and RF device performance in nominally 0.2- mu m gate-length atomic-planar doped pseudomorphic Al/sub 0.30/Ga/sub 0.70/As/In/sub 0.25/Ga/sub 0.75/As MODFETs is reported. Three important results have been obtained: (1) a well width of approximately 120 AA appears to be optimum for overall device performance and gives a current gain cutoff frequency (f/sub T/) of 122 GHz; (2) thinner quantum wells ( approximately 45 AA) result in a significant reduction ( approximately 40%) in maximum channel current density; and (3) thicker quantum wells (150-200 AA), which exceed the critical thickness (90-100 AA) predicted by the Matthews and Blakeslee model, still give excellent device performance (f/sub T/=107 GHz). As a result of the latter, it might be possible to realize much higher-indium-percentage (30-40%) quantum wells without having to reduce the well width to an unacceptable value.< >
ISSN:0018-9383
1557-9646
DOI:10.1109/16.8885