Symmetric Lateral Doping-Free BJT: A Novel Design for Mixed Signal Applications

Next Generation Logic Gate Designs using Improved Polarity Control Bipolar Junction Transistor

“…It can be inferred that both β and f T are decreasing beyond the base length of 120 nm. Moreover, at the optimised base length of 120 nm, on-time voltage of the proposed PC-BJT is 0.45 V which is 28 % less than the device demonstrated in [7]. Beyond the optimised base length, on-time voltage of the proposed device decreases but there is a degradation in both β and f T , hence we chosen base length as 120 nm for the rest of the simulation.…”

“…1(a) shows crosssectional view of the proposed polarity control bipolar junction transistor (PC-BJT), where LB, n+ or p+, tSi, and tB represent the length of base region, emitter or collector regions, silicon thickness, and extended base height, respectively. In contrast to the conventional device based on polarity control [7], the proposed PC-BJT structure differs in terms t B , t Si , L B , emitter/collector length (L E /L C ) and intrinsic gap presence between the emitter-base and base-collector regions. After, all these modifications, the overall length of the proposed device are now reduced to 190 nm compared to the overall length of the conventional device (199 nm).…”

“…PC concepts widely reported in literature for reconfigurability-the capability of changing the polarity (n or p type) [6]. Moreover, to exploit full benefits of this concept, configurable BJT have also been built to exhibit switching between n-i-n to p-ip and vice versa [7] [8]. Hence, due to polarity control, problems associated with CP concept in BJT devices have now been resolved, and also have opened the integration possibility with other devices [9] [10] [11].…”

“…However, β of PC based devices are very poor compared to those devices that are based on CP concept. Moreover, very high on-time voltage (>0.6 V) required to switch-on the PC based devices results increment in input voltage required to extract both current gain (β) and cut-off frequency (f T ) [7].…”

Impact of Work Function Engineering in Charge Plasma Based Bipolar Devices

“…In addition, bipolar charge plasma transistors (BCPTs) in symmetric nature have also been proposed to make it compatible with symmetric MOSFETs [6], [7]. Moreover, polarity controlled reconfigurable BCPTs that can switch from NPN type to PNP type and vice versa also have contributed to this [8]- [10]. But bipolar devices based on the charge plasma concept have had reported comparatively very large current gain [7], [8] and half of the cutoff frequency compared to its counterparts [5].…”