In a semiconductor storage device, a first ROM cell includes a first nanosheet FET having a first nanosheet as the channel region, provided between a first bit line and a first ground power supply line. A second ROM cell includes a second nanosheet FET having a second nanosheet as the channel region, provided between a second bit line and a second ground power supply line. The face of the first nanosheet closer to the second nanosheet in the X direction is exposed from a first gate interconnect, and the face of the second nanosheet closer to the first nanosheet in the X direction is exposed from a second gate interconnect.

Various implementations described herein are related to a device with a backside power network. The backside power network may have a buried power rail that is coupled to ground. The device may have a read-only memory (ROM) cell that is coupled between at least one bitline and the buried power rail, and the ROM cell may be coupled to ground by way of the buried power rail.

A layout structure of a ROM cell using a complementary FET (CFET) is provided. The ROM cell includes first and second three-dimensional transistors. The second transistor is formed above the first transistor, and the channel portions of the first and second transistors overlap each other. First data is stored in the ROM cell depending on the presence or absence of connection between a local interconnect connected to the source of the first transistor and a ground power supply line, and second data is stored in the ROM cell depending on the presence or absence of connection between a local interconnect connected to the source of the second transistor and a ground power supply line.

An integrated circuit read only memory (ROM) structure includes a first ROM transistor with a first gate electrode, a first source, and a first drain, and a second ROM transistor with a second gate electrode, a second source, and a second drain. A drain conductive line is over the first drain and the second drain, and is between the first drain and the second drain. The first drain, the drain conductive line and the second drain are between the first gate electrode and the second gate electrode, and a first trench isolation structure electrically isolates the first drain from the first source is below the first gate electrode.

A memory circuit includes first and second active structures extending along a first direction. The first active structure has a shared source portion and first and second drain portions corresponding to source and drain nodes of first and second memory cells. The second active structure has a shared source portion and third and fourth drain portions corresponding to source and drain nodes of third and fourth memory cells. A first conductive structure extends along a second direction and electrically connects the shared source portions of the first and second active structures, and first and second bit lines extend over the first and second active structures. A via plug is part of a direct electrical connection between the first bit line and one of the first or second drain portions or between the second bit line and one of the third or fourth drain portions.

A memory circuit includes first and second read-only memory (ROM) cells aligned along a first active structure including a first shared source portion of the first and second ROM cells, third and fourth ROM cells aligned along a second active structure including a second shared source portion of the third and fourth ROM cells, a first bit line overlying the first and second ROM cells, a second bit line overlying the third and fourth ROM cells, and a reference voltage line positioned between the first and second bit lines and in a same metal layer as the first and second bit lines. A conductive structure is electrically connected to each of the first and second shared source portions and the reference voltage line and is positioned in a metal layer below the same metal layer.

Provided is a read-only memory (ROM) device. The ROM device comprises a substrate that has a plurality of vertical transport field effect transistors (VFETs). The ROM device further comprises an un-activated semiconductor layer provided on each VFET. The un-activated semiconductor layer includes implanted dopants that have not been substantially activated.

An integrated circuit read only memory (ROM) structure includes a first ROM transistor with a first gate electrode, a first source, and a first drain, and a second ROM transistor with a second gate electrode, a second source, and a second drain. A drain conductive line is over the first drain and the second drain, and is between the first drain and the second drain. The first drain, the drain conductive line and the second drain are between the first gate electrode and the second gate electrode, and a first trench isolation structure electrically isolates the first drain from the first source is below the first gate electrode.

A layout structure of a small-area one time programmable (OTP) memory using a complementary FET (CFET) is provided. The OTP memory has transistors TP as a program element and transistors TS as a switch element. The transistors TP are three-dimensional transistors of which channel portions overlap each other as viewed in plan. The transistors TS are three-dimensional transistors of which channel portions overlap each other as viewed in plan. The OTP memory of two bits is implemented in a small area.

Provided is a read-only memory (ROM) device. The ROM device comprises a substrate that has a plurality of vertical transport field effect transistors (VFETs). The ROM device further comprises an un-activated semiconductor layer provided on each VFET. The un-activated semiconductor layer includes implanted dopants that have not been substantially activated.