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Verfahren zur Bestimmung der Struktur eines Transistors

Method for determining the structure of a transistor comprising four layers, comprises setting the layer thickness of the second layer, setting the aluminum content of the second layer and producing the second and first layer
 
: Koehler, K.; Mueller, S.; Waltereit, P.

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Frontpage ()

DE 102009028918 A: 20090826
DE 102009028918 A: 20090826
H01L0021
H01L0029
Deutsch
Patent, Elektronische Publikation
Fraunhofer IAF ()

Abstract
(A1) Die Erfindung betrifft ein Verfahren zur Bestimmung der Struktur mindestens eines Transistors, welcher zumindest eine erste Schicht, eine zweite Schicht und eine vierte Schicht enthaelt, wobei die vierte Schicht auf der zweiten Schicht und die zweite Schicht auf der ersten Schicht angeordnet ist, die erste Schicht GaN enthaelt, die zweite Schicht AlxGa1-xN und die vierte Schicht ein Metall oder eine Legierung enthaelt, wobei das Verfahren die folgenden Schritte enthaelt: Festlegen der Schichtdicke der zweiten Schicht, Festlegen des Aluminium-Gehaltes x der zweiten Schicht, Herstellen von zumindest der zweiten Schicht und der ersten Schicht, Bestimmen der Oberflaechenpotentials $I1 und/oder der Ladungstraegerdicht ns und/oder der Ladungstraegerbeweglichkeit ? nach der Herstellung der zweiten Schicht und der ersten Schicht und Auswaehlen des Materials der vierten Schicht in Abhaengigkeit des zumindest einen Messergebnisses.

 

WO 2011023607 A1 UPAB: 20110321 NOVELTY - The method for determining the structure of a transistor comprising a first layer (11) made of gallium nitride, a second layer (12) made of aluminum-gallium-nitride, and a fourth layer (14) made of metal or alloy, comprises setting the layer thickness of the second layer, setting the aluminum content x of the second layer, producing the second layer and the first layer, determining the surface potential and/or the charge carrier density and/or the charge carrier motility after producing the second layer and the first layer, and selecting the material of the fourth layer. DETAILED DESCRIPTION - The method for determining the structure of a transistor comprising a first layer (11) made of gallium nitride, a second layer (12) made of aluminum-gallium-nitride, and a fourth layer (14) made of metal or alloy, comprises setting the layer thickness of the second layer, setting the aluminum content x of the second layer, producing the second layer and the first layer, determining the surface potential and/or the charge carrier density and/or the charge carrier motility after producing the second layer and the first layer, and selecting the material of the fourth layer in dependent upon the surface potential and/or the charge carrier density. The material of the fourth layer is silver, palladium, nickel and/or platinum. The transistor comprises a third layer (13) made of gallium nitride disposed between the second and fourth layer, which is disposed on the third layer. The third layer is disposed on the second layer, which is disposed on the first layer. The total thickness of the second and third layer is 15-50 nm. The aluminum content is 0.08-0.18. The production process of the third, second and the first layer is molecular beam epitaxy process, metalorganic vapor phase epitaxy process or metal organic chemical vapor deposition process. The thickness and aluminum content of the second layer are increased in order to lower the threshold voltage of the transistor and the thickness and aluminum content of the second layer are reduced in order to increase the threshold voltage of the transistor. The selection of the material of the fourth layer is carried out so that the threshold voltage of the transistor is -4.5 to -1.0 V. An echo effect-measurement and/or the measurement of photo reflexion is carried out. A connection between a changing of surface potential is modelized through applying the fourth layer and a changing of the charge carrier density. The threshold voltage is modelized in dependent on the surface potential after the application of the fourth layer and the charge carrier density. An INDEPENDENT CLAIM is included for a semiconductor component. USE - Method for determining the structure of a transistor useful for base station for a mobile network (claimed). ADVANTAGE - The method ensures simple and efficient determination of the structure of a transistor with good quality.

: http://publica.fraunhofer.de/dokumente/N-159209.html