Methods and apparatus for depositing a metal containing-layer in a semiconductor processing chamber. One example method generally includes delivering a processing gas into the semiconductor processing chamber during a time period, where the processing gas comprises a first precursor delivered at a first rate and etchants delivered at a second rate, sustaining a plasma formed from the first precursor present in the semiconductor processing chamber during at least a first portion of the time period, and depositing the metal containing-layer on at least a portion of a semiconductor structure during the time period until an endpoint thickness is reached. Delivering the processing gas into the semiconductor processing chamber generally includes delivering the first precursor and the etchants during the time period or delivering the first precursor during a first part of the time period and delivering the etchants during a second part of the time period.

A semiconductor device includes a shallow trench isolation (STI), a first well region connected to the insulating region and the STI on a first side, a second well region connected to the insulating region and the STI on a second side, and a backside contact including an upper portion, a lower portion, and a middle portion connecting the upper portion and the lower portion. A shape and a profile of the insulating region is same as a shape and a profile of the middle portion.

A semiconductor device may include an insulating pattern on a first lower interlayer insulating layer, nanosheets vertically stacked on the insulating pattern, a gate electrode on the insulating pattern and surrounding the nanosheets, a source/drain region on one side of the gate electrode on the insulating pattern, and a source/drain contact electrically connected to the source/drain region. The source/drain region, the first lower interlayer insulating layer, and the insulating pattern may define a contact trench and the source/drain contact may fill the contact trench. The source/drain contact may include a barrier layer, a first filling layer between parts of the barrier layer in the contact trench, and a second filling layer in the contact trench under the first filling layer. The first filling layer may be multi grain and may have a first average grain size. The second filling layer may be single grain.

In a contact hole, a first side surface of an interlayer insulating film is separated from a second side surface of a first conductive film so that a part of an upper surface of the first conductive film is exposed from the interlayer insulating film. In the contact hole, a third side surface of an insulating film is separated from the second side surface of the first conductive film so that a part of the lower surface of the first conductive film is exposed from the insulating film. A plug includes a silicide layer formed on the second side surface of the first conductive film, a barrier metal film formed on the silicide layer, and a second conductive film formed on the barrier metal film.