Polysilicon layers have been doped with high uniform concentrations of arsenic in short processing times using gas‐phase doping. The polysilicon layers were doped at total system pressures from 1 to 760 Torr with arsine or tertiarybutylarsine (TBA) as gas‐phase dopant sources. An arsenic concentration as high as ≳4×1020atm/cm3in 100 nm polysilicon layers was measured after a 60 s diffusion in 2.4% arsine in He at 1000 °C at 760 Torr. Using tertiarybutylarsine (TBA) at 3 Torr, a sheet resistance of 2.5 kΩ/⧠ was measured in a 100 nm polysilicon layer after 12 min at 900 °C. Doping at temperatures as low as 770 °C also gave high arsenic concentrations. Finally, a 6 μm deep DRAM trench capacitor was uniformly doped with arsenic to a concentration of 8×1019atm/cm3using gas‐phase doping and a two‐step polysilicon deposition process.