Patent ID: 8653578
Filing Date: 2014-02-18
Classification: H01L

Abstract:
1. A semiconductor device comprising: a substrate having an active region; plurality of memory gates disposed on the active region of the substrate; a ground selection gate located on the active region at a first side of the plurality of memory gates, the ground selection gate having an inner side facing towards one of the plurality of memory gates, and an outer side opposite the inner side thereof; a string selection gate located on the active region at a second side of the plurality of memory gates opposite the first side, the string selection gate having an inner side facing towards another of the plurality of memory gates, and an outer side opposite the inner side thereof; a plurality of first doping regions occupying portions of the active region between the respective memory gates, occupying a portion of the active region between said another of the memory gates and the string selection gate, occupying a portion of the active region between said one of the memory gates and the ground selection gate, occupying a first portion of the active region extending in a first direction away from the outer side of the string selection gate, and occupying a second portion of the active region extending in a second direction opposite the first direction away from the outer side of the ground selection gate; and second doping regions each having impurities of a first conductivity type, a first one of the second doping regions extending in the active region in the first direction from a location directly below the string selection gate beyond the outer side of the string selection gate, and a second one of the second doping regions extending in the active region in the second direction from a location directly below the ground selection gate beyond the outer side of the ground selection gate, wherein all of the first doping regions have impurities of the first conductivity type, the second doping regions are deeper than the first doping regions, the second doping regions have a higher concentration of impurities than the first doping regions that occupy the portions of the active region between the respective memory gates, the first doping region that occupies the first portion of the active region extends in the first direction to a location further from the outer side of the string selection gate than the first one of the second doping regions, the first doping region that occupies the second portion of the active region extends in the second direction to a location further from the outer side of the ground selection gate than the second one of the second doping regions, and the portions of the active region between the memory gates are devoid of impurities of a different conductivity type from the first conductivity type.