Solid solubility limited dopant activation of group III dopants (B, Ga & In) in Ge targeting sub-7nm node low p+ contact resistance
Journal
17th International Workshop on Junction Technology, IWJT 2017
Pages
94-97
Date Issued
2017
Author(s)
Abstract
Low contact resistance (Rc) is key to boost device performance for sub-10nm node. At VLSI Technology Symposium 2016 Samsung reported they reduced Rc by 10% from 14nm to 10nm bulk FinFET technology [1]. TSMC in their beyond 10nm node FinFET paper reported reducing S/D (source/drain) parasitic resistance and enhanced contact process [2] and at IEDM-2016 reported 7nm FinFET reduced S/D parasitic resistance and developed a novel contact process [3]. A complete session #7 was dedicated to 'Contact Resistance Innovations for Sub 10nm Scaling' with 4 papers at the VLSI Technology Symposium 2016 [4-7]. To achieve Rc in the low E-9 Ωcm2 requires active dopant carrier concentration >5E20/cm3 to low E21/cm3. For SiP n+ S/D contacts P >1E21/cm3 active dopant carrier concentration is realized with laser melt annealing resulting in Rc <1E-9 Ωcm2 [6]. For 70%-SiGe p+ S/D contacts IMEC reported using pre and post Ge amorphous implants to boost the B-implant activation with nsec laser melt annealing to reduce Rc from 1.2E-8 Ωcm2 to 2.1E-9 Ωcm2 [4]. IBM/GF on the other hand reported reducing SiGe p+ S/D Rc from 1.3E-8 Ωcm2 to 1.9E-9 Ωcm2 by using a thin 12nm 100%-Ge trench-epi and switching from a p+ Ge:B to a p+ Ge:B:group-III metastable alloy for surface interface doping [8]. The group-III Me-alloy in Ge boosted p+ dopant activation from ??E19/cm3 with B to ??E20/cm3 with Ge+Me-alloy. They mentioned no difference between msec non-melt and nsec melt laser annealing. © 2017 JSAP.
Other Subjects
Annealing; Carrier concentration; Chemical activation; Contact resistance; Doping (additives); FinFET; Germanium; Nanotechnology; Silicon alloys; VLSI circuits; Contact process; Device performance; Dopant activation; Metastable alloy; Parasitic resistances; Solid solubilities; Surface interfaces; VLSI technology; Si-Ge alloys
Type
conference paper