| US 7,573,065 B2 | ||
| Semiconductor device evaluation method | ||
| Ryosuke Iijima, Kawasaki (Japan); and Masato Koyama, Kanagawa (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Jun. 22, 2006, as Appl. No. 11/472,449. | ||
| Claims priority of application No. P2005-183235 (JP), filed on Jun. 23, 2005. | ||
| Prior Publication US 2006/0289863 A1, Dec. 28, 2006 | ||
| Int. Cl. H01L 23/58 (2006.01) | ||
| U.S. Cl. 257—48 [257/410] | 4 Claims |
| 1. A method for evaluating a field-effect transistor, comprising:
forming a potential difference between a first terminal electrically connected to a source region of the field-effect transistor
and a second terminal electrically connected to a drain region of the field-effect transistor;
applying monopulse voltage to a gate electrode of the field-effect transistor to change the field-effect transistor from a
depletion state to an inversion state;
measuring temporal change in source current flowing through the first terminal when the monopulse voltage is applied;
measuring temporal change in drain current flowing through the second terminal when the monopulse voltage is applied;
obtaining a channel current in an operating state of the field-effect transistor, based on a current value calculated by dividing
an algebraic difference between the source current and the drain current by 2;
obtaining a quantity of inversion layer charge in the operating state of the field-effect transistor, based on a temporally
integrated current value calculated as an algebraic sum of the source current and the drain current; and
obtaining mobility of a carrier based on the channel current and the quantity of the inversion layer charge.
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