×

Nonvolatile semiconductor memory device with tapered sidewall gate and method of manufacturing the same

  • US 20050085039A1
  • Filed: 07/29/2004
  • Published: 04/21/2005
  • Est. Priority Date: 10/20/2003
  • Status: Active Grant
First Claim
Patent Images

1. A manufacturing method of a nonvolatile semiconductor memory device, comprising the steps of:

  • (a) forming a first insulator over a main surface of a semiconductor substrate, and forming a first gate electrode on said first insulator so that a taper angle on the side of not having said gate electrode between the sidewall surface at the lowermost portion of said gate electrode and the main surface of said semiconductor substrate can be within a range of 95 to 180 degrees except for 180 degrees;

    (b) forming a second insulator over the sidewall of said first gate electrode, and forming a third insulator on the surface of said semiconductor substrate on both sides of said first gate electrode;

    (c) forming a fourth insulator on said second insulator and said third insulator;

    (d) forming a fifth insulator on said fourth insulator; and

    (e) forming a second gate electrode made of a conductive material on the sidewall of said first gate electrode and at a position opposite to said semiconductor surface on one or both sides of said first gate electrode via said second to fifth insulators.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×