Abstract: A semiconductor device and a method of manufacturing the same. The method includes preparing a semiconductor substrate having high-voltage and low-voltage device regions, forming a field insulating layer in the high-voltage device region, forming a first gate oxide layer on the semiconductor substrate, exposing the semiconductor substrate in the low-voltage device region by etching part of the first gate oxide layer and also etching part of the field insulating layer to form a stepped field insulating layer, forming a second gate oxide layer on the first gate oxide layer in the high-voltage device region and on the exposed semiconductor substrate in the low-voltage device region, and forming a gate over the stepped field insulating layer and part of the second gate oxide layer in the high-voltage device region adjoining the field insulating layer.

Abstract: A semiconductor device and a method of manufacturing the same. The method includes preparing a semiconductor substrate having high-voltage and low-voltage device regions, forming a field insulating layer in the high-voltage device region, forming a first gate oxide layer on the semiconductor substrate, exposing the semiconductor substrate in the low-voltage device region by etching part of the first gate oxide layer and also etching part of the field insulating layer to form a stepped field insulating layer, forming a second gate oxide layer on the first gate oxide layer in the high-voltage device region and on the exposed semiconductor substrate in the low-voltage device region, and forming a gate over the stepped field insulating layer and part of the second gate oxide layer in the high-voltage device region adjoining the field insulating layer.