| 摘要 |
PURPOSE: To simply and accurately measure the impurity distribution of a semiconductor in a lateral direction by measuring source and drain voltages under the condition that the gate voltage and the source-drain current are constant for a plurality of MOSFETs having different channel lengths and manufactured by the same process. CONSTITUTION: Let the channel length of a MOSFET 1 be L0 , and the channel length of a MOSFET 2 be (L0 +ΔL). The source voltage and the drain voltage at which the source-drain currents of both MOSFETs are equal to each other under the condition that the gate voltage and wafer voltage are constant are measured. The local threshold value VTH2 at the position of the channel length differenceΔL is obtained by the difference between the MOSFETs 1 and 2. The local impurity concentration when the depth direction distribution of the channel impurity is uniform is obtained based on the threshold value VTH2 . Thus, the impurity concentration of a channel in the lateral direction can be simply and accurately obtained.
|
