Nonvolatile semiconductor memory

Abstract

Abstract PURPOSE:To provide a nonvolatile semiconductor memory of high reliability by providing source and drain regions; a floating gate electrode having the shape of a rectangular frame on a field isolation film and overlapping the source and drain regions; and a gate insulator between the floating gate electrode and the source and drain regions. CONSTITUTION:A floating gate electrode 106 in the shape of a rectangular frame is provided on a field isolation film 102. The gate electrode overlaps a source region 111 and a drain region 121, and a gate insulator 103 is provided between the gate electrode and the source and drain regions. A channel region 131 includes two parts that are controlled by a control gate electrode 107 and the floating gate electrode, respectively. Write and erase operations are available at either the drain region or the source region. Therefore, the stress on the gate insulator 103 during write and erase operations is decreased, resulting in an increased number of allowable repeated operations. The parasitic leakage current through the capacitive coupling between the drain region and the floating gate electrode is cut off by the control electrode.

Inventors

• 👤 Masashi Koyama
• 👤 小山　昌司

Bibliographic Details