Conference Proceeding (25)

• 21:

  Title: Lansbergen GP; Rahman R; Caro J; Collaert N; Biesemans S; Klimeck G; Hollenberg LCL; Rogge S, 2009, '+Level spectrum of single gated as donors', in Caldas MJ; Studart N (eds.), AIP Conference Proceedings, AMER INST PHYSICS, Rio de Janeiro, BRAZIL, pp. 93 - 94, presented at 29th International Conference on Physics of Semiconductors, Rio de Janeiro, BRAZIL, 27 July - 01 August 2008
     

  Year : 2009

  Publication Type: Conference Proceeding

  Topic:

  Abstract

  We study the electrical transport through single As donors incorporated in the channel of a FinFET, i.e. a donor in a three‐terminal geometry. By means of spectroscopic measurements in conjuction with a NEMO‐3D model, we can identify the excited states and associate them with either the donors Coulomb potential, a triangular well at the interface or a hybridized combination of the two. The correspondence between the transport measurements, the theoretical model and the local environment provides an atomic understanding of actual gated donors in a nanostructure.

  View
• 22:

  Title: Lansbergen GP; Rahman R; Wellard CJ; Caro J; Collaert N; Biesemans S; Klimeck G; Hollenberg LCL; Rogge S, 2008, 'Transport-based dopant metrology in advanced FinFETs', in Technical Digest - International Electron Devices Meeting, IEDM, IEEE, San Francisco, CA, pp. 713 - +, presented at IEEE International Electron Devices Meeting, San Francisco, CA, 15 - 17 December 2008
     

  Year : 2008

  Publication Type: Conference Proceeding

  Topic:

  Abstract

  Ultra-scaled FinFET transistors bear unique fingerprint-like device-to-device differences attributed to random single impurities. Through correlation of experimental data with multimillion atom simulations in NEMO 3-D, we can identify the impurity's chemical species and determine their concentration, local electric field and depth below the Si/SiO 2 interface. The ability to model the excited states rather than just the ground states is the critical need. We therefore demonstrate a new approach to atomistic impurity metrology and confirm the assumption of tunneling through individual impurity quantum states.

  View
• 23:

  Title: Lansbergen GP; Rahman R; Wellard CJ; Rutten PE; Caro J; Woo I; Colleart N; Biesemans S; Klimeck G; Hollenberg LCL; Rogge S, 2008, 'Determination of the eigenstates and wavefunctions of a single gated As donor', in Proceedings of the 2008 International Conference on Nanoscience and Nanotechnology, ICONN 2008, pp. 164 - 167
     

  Year : 2008

  Publication Type: Conference Proceeding

  Topic:

  Abstract

  Current semiconductor devices have been scaled to such dimensions that we need take atomistic approach to understand their operation for nano-electronics. From a bottoms-up perspective, the smallest functional element within a nanodevice would be a single (dopant) atom itself. Control and understanding over the eigenenergies and wavefunctions of a single dopant could prove a key ingredient for device technology beyond-CMOS. Here, we will discuss the eigenlevels of a single As donor in a three terminal configuration. The donor is incorporated in the channel of prototype transistors called FinFETs. The measured eigenlevels are shown to consist of levels associated with the donors Coulomb potential, levels associated with a triangular well at the gate interface and hybridized combinations of the two. The theoretical framework in which we describe this system (NEMO-3D) is based on a tight-binding approximation.

  View
• 24:

  Title: Lansbergen P; Rahman R; Caro J; Biesemans S; Klimeck G; Hollenberg L; Rogge S, 2008, 'Transport spectroscopy of a single atom in a FinFET', in Journal of Physics: Conference Series
     

  Year : 2008

  Publication Type: Conference Proceeding

  Topic:

  Abstract

  Current semiconductor devices have been scaled to such dimensions that we need to look at them atomistically to understand their operation for nanoelectronics. At the same time this also brings new opportunities such as electrical access to a single dopant. This paper focusses on the physics of transport through a single n-type dopant in a semiconductor and the gate control of the wavefunction of this atom. Understanding and controlling a dopant's wavefunction in a nanostructure is a key ingredient of Si quantum electronics. In our experimental system we are sensitive to only a single As donor incorporated in the channel of a Si triple-gate transistor and measure the level spectrum and charging energy by means of transport spectroscopy. These levels can be assigned to the dopant, a triangular well at the interface and hybridized combinations of those two. The assignment is based on atomistic modeling of the dopant close to the interface in a tight binding approach.

  View
• 25:

  Title: Ahmed S; Usman M; Heitzinger C; Rahman R; Schliwa A; Klimeck G, 2007, 'Symmetry breaking and fine structure splitting in zincblende quantum dots: Atomistic simulations of long-range strain and piezoelectric field', in AIP Conference Proceedings, pp. 849 - 850
     

  Year : 2007

  Publication Type: Conference Proceeding

  Topic:

  Abstract

  Electrons and holes captured in self‐assembled quantum dots (QDs) are subject to symmetry breaking that cannot be represented in with continuum material representations. Atomistic calculations reveal symmetry lowering due to effects of strain and piezo‐electric fields. These effects are fundamentally based on the crystal topology in the quantum dots. This work studies these two competing effects and demonstrates the fine structure splitting that has been demonstrated experimentally can be attributed to the underlying atomistic structure of the quantum dots.

  View