Abstract: A method for forming a bipolar transistor device includes providing a semiconductor substrate. An oxide layer is formed on the semiconductor substrate. The oxide layer is patterned to form an opening that exposes a portion of the semiconductor substrate. A dopant, such as antimony, is implanted into the semiconductor substrate through the opening to form a buried layer. An upper portion of the mask layer is removed to define a thin mask layer. A buried layer diffusion process is performed to drive in the implanted dopants while mitigating recess formation.

Abstract: A method for forming a bipolar transistor device includes providing a semiconductor substrate. An oxide layer is formed on the semiconductor substrate. The oxide layer is patterned to form an opening that exposes a portion of the semiconductor substrate. A dopant, such as antimony, is implanted into the semiconductor substrate through the opening to form a buried layer. An upper portion of the mask layer is removed to define a thin mask layer. A buried layer diffusion process is performed to drive in the implanted dopants while mitigating recess formation.