Method of measuring resistance in deep trench

摘要

A method of measuring resistance in a deep trench. A first substrate having a first trench with a first depth is provided. A first collar insulating layer is formed on the sidewall of the first trench. A first polysilicon layer is formed in the first trench and on the first substrate to obtain a first polysilicon plug in the first trench. The first polysilicon layer and the first substrate are doped with impurity ions, and a first N well is formed in the first substrate. The above procedures are repeated to obtain a second substrate having a second trench with a second depth not equal to the first depth. A voltage is applied to the first and second substrates respectively to obtain a first total resistance of the first substrate and a second total resistance of the second substrate. Finally, the first total resistance and second total resistance are converted by calculation to obtain a resistance of the first polysilicon plug and a resistance of the second polysilicon plug.