Analyzing Carrier Density and Hall Mobility in Impurity-Free Silicon Virtually Doped by External Defect Placement

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Soundarya Nagarajan - , Chair of Nanoelectronics, NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Ingmar Ratschinski - , Freiberg University of Mining and Technology (Author)
  • Stefan Schmult - , Chair of Nanoelectronics (Author)
  • Steffen Wirth - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Dirk König - , Australian National University, RWTH Aachen University (Author)
  • Thomas Mikolajick - , Chair of Nanoelectronics, NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Daniel Hiller - , Freiberg University of Mining and Technology (Author)
  • Jens Trommer - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)

Abstract

Impurity doping at the nanoscale for silicon is becoming less efficient with conventional techniques. Here, an alternative virtual doping method is presented for silicon that can achieve an equivalent carrier density while addressing the primary limitations of traditional doping methods. The doping for silicon is carried out by placing aluminum-induced acceptor states externally in a silicon dioxide dielectric shell. This technique can be referred to as direct modulation doping. The resistivity, carrier density, and mobility are investigated by Hall effect measurements to characterize the carrier transport using the new doping method. The results thereof are compared with carrier transport analysis of conventionally doped silicon at room-temperature, demonstrating a 100% increase in carrier mobility at equal carrier density. The sheet density of hole carriers in silicon due to modulation doping remains nearly constant, ≈4.7 × 1012 cm−2 over a wide temperature range from 300 down to 2 K, proving that modulation-doped devices do not undergo carrier freeze-out at cryogenic temperatures. In addition, a mobility enhancement is demonstrated with an increase from 89 cm2 Vs−1 at 300 K to 227 cm2 Vs−1 at 10 K, highlighting the benefits of the new method for creating emerging nanoscale electronic devices or peripheral cryo-electronics to quantum computing.

Details

Original languageEnglish
Article number2415230
JournalAdvanced functional materials
Volume35
Issue number7
Publication statusPublished - 12 Feb 2025
Peer-reviewedYes

External IDs

ORCID /0000-0003-3814-0378/work/180371982

Keywords

Keywords

  • carrier density, carrier freeze-out, cryogenic electronics, Hall effect, mobility, modulation doped silicon-based heterostructure, quantum interfaces, scattering mechanisms