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

Advanced Functional Materials, vol. 35

Abstract

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.

Authors 8

1. Soundarya Nagarajan

   NaMLab (Germany) · Technische Universität Dresden

   Affiliation as printed

   NaMLab gGmbH Nöthnitzer Str. 64a 01187 Dresden Germany

   Technische Universität Dresden Electrical and Computer Engineering Institute of Semiconductors and Microsystems Nöthnitzer Str.64 01187 Dresden Germany

2. Ingmar Ratschinski

   TU Bergakademie Freiberg

   Affiliation as printed

   Technische Universität Bergakademie Freiberg Institute of Applied Physics (IAP) Leipziger Str. 23 09599 Freiberg Germany

3. S. Schmult

   Technische Universität Dresden

   Affiliation as printed

   Technische Universität Dresden Electrical and Computer Engineering Institute of Semiconductors and Microsystems Nöthnitzer Str.64 01187 Dresden Germany

4. S. Wirth

   Max Planck Institute for Chemical Physics of Solids

   Affiliation as printed

   Max Planck Institute for Chemical Physics of Solids Dresden Nöthnitzer Str. 40 01187 Dresden Germany

5. Dirk König Aachen Institute of Semiconductor Electronics

   Australian National University · RWTH Aachen University

   Affiliation as printed

   Institute of Semiconductor Electronics (IHT) RWTH Aachen University 52074 Aachen Germany

   Integrated Materials Design Lab (IMDL) Australian National University (ANU) Canberra ACT 2601 Australia

   Institute of Semiconductor Electronics (IHT), RWTH Aachen University, 52074 Aachen, Germany

   Integrated Materials Design Lab (IMDL), Australian National University (ANU), Canberra, ACT, 2601 Australia

6. Thomas Mikolajick

   NaMLab (Germany) · Technische Universität Dresden

   Affiliation as printed

   NaMLab gGmbH Nöthnitzer Str. 64a 01187 Dresden Germany

   Technische Universität Dresden Electrical and Computer Engineering Institute of Semiconductors and Microsystems Nöthnitzer Str.64 01187 Dresden Germany

7. Daniel Hiller

   TU Bergakademie Freiberg

   Affiliation as printed

   Technische Universität Bergakademie Freiberg Institute of Applied Physics (IAP) Leipziger Str. 23 09599 Freiberg Germany

8. Jens Trommer corresponding

   NaMLab (Germany)

   Affiliation as printed

   NaMLab gGmbH Nöthnitzer Str. 64a 01187 Dresden Germany