Improvement of RF Performance by Using Tunnel Diode Body Contact Structure in PD SOI nMOSFETs

Abstract

Radio-frequency (RF) performance of multi-finger partially depleted silicon-on-insulator (SoI) nMOSFETs with tunnel diode body contact (TDBC) structure is investigated in this letter. The TDBC structure suppresses floating-body effect and body instability significantly and shows less drain conductance degradation with respect to FB and TB devices. The peak cutoff frequency (f T ) and maximum oscillation frequency (f MAX ) of TDBC devices are 96.4 and 132.8 GHz, respectively. Due to lower parasitic resistances and capacitances, the device with TDBC structures represents an improvement of 10% for the f T and of 90% for the f MAX compared with conventional T-gate body-contact devices. The investigation results indicate that TDBC SoI MOSFETs are a good candidate for analog and RF applications.Index Terms-Radio-frequency (RF), tunnel diode, body contact, floating body, partially depleted silicon-on-insulator.

Effects of back gate bias on radio-frequency performance in partially depleted silicon-on-inslator nMOSFETs

“…[1] Although SOI metal-oxide semiconductor field-effect transistors (MOS-FETs) suffer floating body effect (FBE) caused by impactionization which restricts the application in analog integrated circuits, the body contacts with different structures are investigated to suppress FBE, such as T-gate (TB), H-gate, bodytied-source, etc. As we previously reported, [2] tunnel diode body-contact (TDBC) structures suppress the FBE successfully without adding additional parasitics compared with the conventional body-contact structures. TDBC structure could also achieve a similar cut-off frequency ( f T ) and even better maximum frequency of oscillation ( f max ) due to smaller parasitic gate-source capacitance.…”

Enhanced Critical Electrical Characteristics in a Nanoscale Low-Voltage SOI MOSFET With Dual Tunnel Diode

“…Recently, a novel structure called tunnel diode body contact (TDBC) SOI structure has been realized to reduce the FBE [13], [14]. This structure uses the tunnel diode concept in the source region.…”

“…Inserting a p + -type region inside the source region forms a tunnel diode for discharging the accumulated holes. Table III illustrates a performance comparison between the structure based on [13] and [14] and the DTD-SOI structure. In other works, the novel structures called Embedded Junction Field Effect Transistor (EJFET)-SOI MOSFET (EJFET-SOI) [15] and SOI with inserted InAs layer (IIS-SOI) [16] have been introduced to reduce the FBE.…”

“…In addition, in [16], a n + -type InAs material is inserted inside the source to reduce the FBE. Despite introducing the TDBC-SOI [13], [14], EJFET-SOI [15], and IIS-SOI [16] as novel candidates for reduction of the FBE, the DTD-SOI structure proposed in this brief has much better electrical and thermal performance than three other structures, as shown in Table III. Regarding Table III, the DIBL is considerably reduced in the DTD-SOI structure when compared with other structures.…”

Ultra-low temperature radio-frequency performance of partially depleted silicon-on-insulator n-type metal–oxide–semiconductor field-effect transistors with tunnel diode body contact structures

“…[5] In contrast from the conventional body contact structure, TDBC structure efficiently suppresses FBE and body-instability problems with smaller areas compared with TB structure and achieves better f T and f MAX with respect to smaller parasitic gate-source capacitance. [6] The TDBC structure also shows excellent immunity of back gate bias effect [7] compared with FB and TB devices. Most importantly, the fabrication process of TDBC structure is fully compatible with the usual SOI CMOS technology.…”