An embodiment device includes: first fins protruding from an isolation region; second fins protruding from the isolation region; a first fin spacer on a first sidewall of one of the first fins, the first fin spacer disposed on the isolation region, the first fin spacer having a first spacer height; a second fin spacer on a second sidewall of one of the second fins, the second fin spacer disposed on the isolation region, the second fin spacer having a second spacer height, the first spacer height greater than the second spacer height; a first epitaxial source/drain region on the first fin spacer and in the first fins, the first epitaxial source/drain region having a first width; and a second epitaxial source/drain region on the second fin spacer and in the second fins, the second epitaxial source/drain region having a second width, the first width greater than the second width.

A disclosed memory structure includes a first memory region including a first memory array of SRAM memory devices, a second memory region including a second memory array of 1T1C memory devices, and a third memory region including a third memory array of FeFET memory devices. The memory structure further includes at least one data bus laterally extending across the first memory region, the second memory region, and third memory region and configured to provide data transfer among the first memory array, the second memory array, and the third memory array. The memory structure further includes a plurality of peripheral circuit devices formed at a semiconductor material layer of the memory structure, the peripheral circuit devices configured to control the first memory array, the second memory array, and the third memory array. At least one of the second memory array and the third memory array may be a 3-dimensional memory array.

Embodiments of bonded unified semiconductor chips and fabrication and operation methods thereof are disclosed. In an example, a method for forming a unified semiconductor chip is disclosed. A first semiconductor structure is formed. The first semiconductor structure includes one or more processors, an array of embedded DRAM cells, and a first bonding layer including a plurality of first bonding contacts. A second semiconductor structure is formed. The second semiconductor structure includes an array of NAND memory cells and a second bonding layer including a plurality of second bonding contacts. The first semiconductor structure and the second semiconductor structure are bonded in a face-to-face manner, such that the first bonding contacts are in contact with the second bonding contacts at a bonding interface.

A semiconductor structure includes an array of two-port (TP) SRAM cells, each of which includes a write port and a read port. The write port includes two write pass gate (W_PG) transistors, two write pull-down (W_PD) transistors, and two write pull-up (W_PU) transistors. The array of TP SRAM cells includes first and second TP SRAM cells whose write ports abuts each other. Two W_PG transistors of the first and second TP SRAM cells share a common gate electrode. Source/drain electrodes of two W_PD transistors of the first and second TP SRAM cells share a common contact. The first TP SRAM cell includes a Vss conductor connected to the common contact. The second TP SRAM cell includes a write word line (W_WL) landing pad connected to the common gate electrode. The Vss conductor and the W_WL landing pad are located at a first metal layer.

A memory device includes a memory array having a plurality of memory cells arranged along a plurality of rows extending in a row direction and a plurality of columns extending in a column direction. The memory array also includes a plurality of write assist cells connected to the plurality of memory cells. At least one write assist cell of the plurality of write assist cells is in each of the plurality of columns and connected to respective ones of the plurality of memory cells in a same column.

A method for manufacturing a semiconductor device is provided. The method includes forming a material layer over a semiconductor substrate; forming a plurality of spacer masks over the material layer; patterning the material layer into a plurality of masks below the spacer masks, wherein patterning the material layer comprises an atomic layer etching (ALE) process; and etching the semiconductor substrate through the masks.

A semiconductor device includes a substrate with first and second areas, a first trench in the first area, and first and second PMOS transistors in the first area and the second area, respectively. The first transistor includes a first gate insulating layer, a first TiN layer on and contacting the first gate insulating layer, and a first gate electrode on and contacting the first TiN layer. The second transistor includes a second gate insulating layer, a second TiN layer on and contacting the second gate insulating layer, and a first TiAlC layer on and contacting the second TiN layer. The first gate insulating layer, the first TiN layer, and the first gate electrode are within the first trench. The first gate electrode does not include aluminum. A threshold voltage of the first transistor is smaller than a threshold voltage of the second transistor.

A method includes: abutting a first logic cell having a first cell height to a first memory cell having the first cell height; forming a first conductive rail and a second conductive rail at opposite sides of the first memory cell, respectively; forming a plurality of first conductive rails between the first conductive rail and the second conductive rail; forming a third conductive rail and a fourth conductive rail at opposite sides of the first logic cell, respectively; and forming a plurality of second conductive rails between the third conductive rail and the fourth conductive rail. An amount of the plurality of second conductive rails is larger than an amount of the plurality of first conductive rails.

Embodiments of the present disclosure relates to an integrated circuit including an array of memory cells connected to word lines and bit lines located on opposite sides of the memory cells. The memory cell may include gate all around transistors. A memory circuit according to the present disclosure also includes edge cells having word line tap structures configured to connect front side word lines with back side word lines. Some embodiments of the present disclosure provide an IC chip having memory cells with power rail on the front side and logic cells with power rail on the back side.

A method includes forming a first transistor including forming a first gate stack, epitaxially growing a first source/drain region on a side of the first gate stack, and performing a first implantation to implant the first source/drain region. The method further includes forming a second transistor including forming a second gate stack, forming a second gate spacer on a sidewall of the second gate stack, epitaxially growing a second source/drain region on a side of the second gate stack, and performing a second implantation to implant the second source/drain region. An inter-layer dielectric is formed to cover the first source/drain region and the second source/drain region. The first implantation is performed before the inter-layer dielectric is formed, and the second implantation is performed after the inter-layer dielectric is formed.