A method of forming semiconductor devices having improved work function layers and semiconductor devices formed by the same are disclosed. In an embodiment, a method includes depositing a gate dielectric layer on a channel region over a semiconductor substrate; depositing a first p-type work function metal on the gate dielectric layer; performing an oxygen treatment on the first p-type work function metal; and after performing the oxygen treatment, depositing a second p-type work function metal on the first p-type work function metal.

A semiconductor device having a gate structure and a method of forming same are provided. The semiconductor device includes a substrate and a gate structure over the substrate. The substrate has a first region and a second region. The gate structure extends across an interface between the first region and the second region. The gate structure includes a first gate dielectric layer over the first region, a second gate dielectric layer over the second region, a first work function layer over the first gate dielectric layer, a barrier layer along a sidewall of the first work function layer and above the interface between the first region and the second region, and a second work function layer over the first work function layer, the barrier layer and the second gate dielectric layer. The second work function layer is in physical contact with a top surface of the first work function layer.

Integrated circuit structures having source or drain structures with a high germanium concentration capping layer are described. In an example, an integrated circuit structure includes source or drain structures including an epitaxial structure embedded in a fin at a side of a gate stack. The epitaxial structure has a lower semiconductor layer and a capping semiconductor layer on the lower semiconductor layer with an abrupt interface between the capping semiconductor layer and the lower semiconductor layer. The lower semiconductor layer includes silicon, germanium and boron, the germanium having an atomic concentration of less than 40% at the abrupt interface. The capping semiconductor layer includes silicon, germanium and boron, the germanium having an atomic concentration of greater than 50% at the abrupt interface and throughout the capping semiconductor layer.

Integrated circuit structures having source or drain structures with a high germanium concentration capping layer are described. In an example, an integrated circuit structure includes source or drain structures including an epitaxial structure embedded in a fin at a side of a gate stack. The epitaxial structure has a lower semiconductor layer and a capping semiconductor layer on the lower semiconductor layer with an abrupt interface between the capping semiconductor layer and the lower semiconductor layer. The lower semiconductor layer includes silicon, germanium and boron, the germanium having an atomic concentration of less than 40% at the abrupt interface. The capping semiconductor layer includes silicon, germanium and boron, the germanium having an atomic concentration of greater than 50% at the abrupt interface and throughout the capping semiconductor layer.

A device comprises a column of cells disposed in multiple levels of word lines including a pillar comprising a first vertical conductive line, a second vertical conductive line, and a vertical semiconductor body disposed between and in contact with the first and second vertical conductive lines. A pillar select line is adjacent to and separated by a gate dielectric from the vertical semiconductor body to form a pillar select switch, the pillar select line disposed beneath the first and second vertical conductive lines. A bottom select line is disposed beneath the first and second vertical conductive lines and insulated from the pillar select line and the first and second vertical conductive lines. The bottom select line is in current-flow contact with the vertical semiconductor body of the pillar.

A device comprises a column of cells disposed in multiple levels of word lines including a pillar comprising a first vertical conductive line, a second vertical conductive line, and a vertical semiconductor body disposed between and in contact with the first and second vertical conductive lines. A pillar select line is adjacent to and separated by a gate dielectric from the vertical semiconductor body to form a pillar select switch, the pillar select line disposed beneath the first and second vertical conductive lines. A bottom select line is disposed beneath the first and second vertical conductive lines and insulated from the pillar select line and the first and second vertical conductive lines. The bottom select line is in current-flow contact with the vertical semiconductor body of the pillar.

A memory array comprising strings of memory cells comprises a vertical stack comprising alternating insulative tiers and conductive tiers. The strings of memory cells in the stack comprise channel-material strings and storage-material strings extending through the insulative tiers and the conductive tiers. At least some of the storage material of the storage-material strings in individual of the insulative tiers are intrinsically less charge-transmissive than is the storage material in the storage-material strings in individual of the conductive tiers. Other aspects, including method, are disclosed.

A memory array comprising strings of memory cells comprises a vertical stack comprising alternating insulative tiers and conductive tiers. The strings of memory cells in the stack comprise channel-material strings and storage-material strings extending through the insulative tiers and the conductive tiers. At least some of the storage material of the storage-material strings in individual of the insulative tiers are intrinsically less charge-transmissive than is the storage material in the storage-material strings in individual of the conductive tiers. Other aspects, including method, are disclosed.

A method used in forming a memory array comprising strings of memory cells comprises forming a conductor tier comprising conductor material on a substrate. Laterally-spaced memory-block regions are formed and individually comprise a vertical stack comprising alternating first tiers and second tiers directly above the conductor tier. Channel-material strings of memory cells extend through the first tiers and the second tiers. Horizontally-elongated lines are formed in the conductor material between the laterally-spaced memory-block regions. The horizontally-elongated lines are of different composition from an upper portion of the conductor material that is laterally-between the horizontally-elongated lines. After the horizontally-elongated lines are formed, conductive material of a lowest of the first tiers is formed that directly electrically couples together the channel material of individual of the channel-material strings and the conductor material of the conductor tier. Other embodiments, including structure independent of method, are disclosed.

A process to form a HEMT can have a gate electrode layer that initially has a plurality of spaced-apart doped regions. In an embodiment, any of the spaced-apart doped regions can be formed by depositing or implanting p-type dopant atoms. After patterning, the gate electrode can include an n-type doped region over the p-type doped region. In another embodiment a barrier layer can underlie the gate electrode and include a lower film with a higher Al content and thinner than an upper film. In a further embodiment, a silicon nitride layer can be formed over the gate electrode layer and can help to provide Si atoms for the n-type doped region and increase a Mg:H ratio within the gate electrode. The HEMT can have good turn-on characteristics, low gate leakage when in the on-state, and better time-dependent breakdown as compared to a conventional HEMT.