Transistor and methods of forming transistors

A transistor comprises a top source/drain region, a bottom source/drain region, a channel region vertically between the top and bottom source/drain regions, and a gate operatively laterally-adjacent the channel region. An upper material is directly above a lower material. The upper material is in at least one of the top source/drain region, the bottom source/drain region, and the channel region. The lower material is in at least one of the top source/drain region, the bottom source/drain region, and the channel region. The upper material comprises 1 atomic percent to 10 atomic percent elemental-form H and 0 total atomic percent to less than 0.1 total atomic percent of one or more noble elements. The lower material comprises 0 atomic percent to less than 1 atomic percent elemental-form H and 0.1 total atomic percent to 10 total atomic percent of one or more noble elements. Other embodiments, including method, are disclosed.