Voltage contrast inspection of an electrical defect on a semiconductor wafer with X-ray photoelectron spectroscopy and an electron beam

Abstract

Highly efficient semiconductor metrology and inspection techniques have played important roles for the early detection of defects in the semiconductor-fabrication industry. We here report a new voltage contrast inspection technique based on X-ray photoelectron spectroscopy (XPS) and an electron beam (XPS/EB-VCI). This technique detects an electrical defect (in particular, an electrically open defect) on a semiconductor wafer while simultaneously analyzing the chemical state of the wafer. In XPS/EB-VCI, the existence of an electrical defect is identified in a wide area on the sub-millimeter scale, and the location of the defect can be specified with micrometerlevel precision. Furthermore, with the application of Auger electron spectroscopy, the identified electrical defect area can be further mapped on the nanometer scale. We believe that XPS/EB-VCI could become a viable assessment tool for the semiconductor inspection process, along with a current inspection technique based on scanning electron microscopy.