| 摘要 |
<p>PURPOSE:To obtain a wide dynamic range and to rapidly measure by providing a square wave generator connected to a gate electrode and a logarithmic amplifier connected to a source (or a drain) electrode. CONSTITUTION:A predetermined voltage Vd is applied from a constant-voltage power source 6 to the drain electrode DO (or the source electrode SO) of a transistor to be inspected, and a square wave such as a sawtooth wave, etc., is input from a square wave generator 7 to the gate electrode GE. The waveform obtained from the electrode SO (or the electrode GE) is measured by a logarithmic amplifier 8 having a large dynamic range. Thus, the transistor characteristics of the extremely wide fine current range of a measuring range can be accurately measured by special calculation and evaluated. Accordingly, this apparatus can be applied to the evaluation of a thin film transistor which is required for the six digit or more dynamic range in a fine current range like the dynamic characteristics of the thin film transistor for a liquid crystal display unit.</p> |
