Observation of deep contact holes and conductive components underlying insulator in a memory cell by tunneling acoustic microscopy

Abstract

We have observed memory cells using tunneling acoustic microscopy (TAM). Ground-connected conductive components underlying an insulator are visible with electrostatic force imaging of TAM. Simultaneously, the contours of the memory cells with contact holes ∼2-μm-deep and ∼0.3 μm in diameter at the bottom are clearly imaged with a commonly used tip.