Arsenic-spike epilayer technology applied to bipolar transistors

Abstract

Abstract-For the first time, epilayers with an arsenic-doped spike of 50 nm width have been grown and used in silicon bipolar junction transistors (BJTs). The epilayer has been optimized such that the collector-base junction of the BJT is formed within the arsenic spike. The counterdoping of boron out-diffusion by arsenic strongly reduces the basewidth. The portion of the spike that is not counterdoped increases the total amount of n-type doping in the collector without reducing ceo . The increased collector-doping allows a 60% higher collector current prior to T fall-off. Arsenic has a low diffusivity so very few constraints are put on the thermal budget of the final process. This high flexibility makes the presented epilayer technology a promising candidate to enhance a bipolar process significantly.

Versatile N-Type Profile Engineering by Controlling Arsenic Surface Segregation in Silicon RPCVD

“…The decrease of the deposition rate with As surface coverage is governed by the same physical principle as the decrease in the growth rate. It was already shown that As deposition stops after forming a full monolayer [9], and this form of the deposition rate was chosen according to the typically observed dependence of the sticking coefficient on coverage [8]. In Fig.…”

Arsenic-Doped High-Resistivity-Silicon Epitaxial Layers for Integrating Low-Capacitance Diodes

“…However, using arsine is challenging due to its strong tendency to segregate on the surface and subsequent auto-doping behavior. Past work has shown that these properties can be controlled and applied with benefit to create special doping profiles [ 8 , 9 ]. Here a technique is developed for a controlled segregation, removal and auto-doping of As to obtain the required very lowly-doped profiles.…”