Investigation of the Passivation Layers Influence on Capacitance Characteristics of AlGaN/GaN Heterostructures
https://doi.org/10.17073/1609-3577-2015-2-137-145
Abstract
AlGaN/GaN heterostructures grown by MOCVD method on sapphire and silicon substrates were test subjects. The capacity− voltage characteristic measurements have been run in 200Hz — 1MHz frequency range at planar disposition of mercury and second probe on the sample surface. The shape of typical C−V curves for the heterostructures with the upper undoped i−AlGaN and i−GaN layers at thickness 15—25 A have been analyzed. The appearance of a typical peak on the C−V curves at changing from depletion region to accumulation region has been registered for some structures with thickness of i−GaN layer 50A at low frequencies (f < 50—200 kHz). The height of this peak increased with reduction of frequency. It has been found experimentally that frequency at which the peak is registered can depend on the dislocation density in heterostructures. Possible explanation of the peak formation and band diagram modifications in these structures under an applied electric field have been presented. We show that using a Si3N4 passivation layer results in the formation of additional positive charge.
About the Authors
K. L. Enisherlova
JSC «S&PE «Pulsar»
Russian Federation
Russian Federation
Dr. Sci. (Eng.), Head of Laboratory,
27 Okruzhnoi proezd, Moscow 105187
V. G. Goryachev
JSC «S&PE «Pulsar»
Russian Federation
Russian Federation
Senior Researcher,
27 Okruzhnoi proezd, Moscow 105187
T. F. Rusak
JSC «S&PE «Pulsar»
Russian Federation
Russian Federation
Senior Researcher,
27 Okruzhnoi proezd, Moscow 105187
S. A. Kapilin
JSC «S&PE «Pulsar»
Russian Federation
27 Okruzhnoi proezd, Moscow 105187
Russian Federation
27 Okruzhnoi proezd, Moscow 105187
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Review
For citations:
Enisherlova K.L., Goryachev V.G., Rusak T.F., Kapilin S.A. Investigation of the Passivation Layers Influence on Capacitance Characteristics of AlGaN/GaN Heterostructures. Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering. 2015;18(2):137-145. (In Russ.) https://doi.org/10.17073/1609-3577-2015-2-137-145
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