In Situ Patterning of Ultrasharp Dopant Profiles in Silicon.

We develop a method for patterning a buried two-dimensional electron gas (2DEG) in silicon using low kinetic energy electron stimulated desorption (LEESD) of a monohydride resist mask. A buried 2DEG forms as a result of placing a dense and narrow profile of phosphorus dopants beneath the silicon surface; a so-called δ-layer. Such 2D dopant profiles have previously been studied theoretically, and by angle-resolved photoemission spectroscopy, and have been shown to host a 2DEG with properties desirable for atomic-scale devices and quantum computation applications. Here we outline a patterning method based on low kinetic energy electron beam lithography, combined with in situ characterization, and demonstrate the formation of patterned features with dopant concentrations sufficient to create localized 2DEG states.

[1]  M. Simmons,et al.  Direct measurement of the band structure of a buried two-dimensional electron gas. , 2013, Physical review letters.

[2]  M. Y. Simmons,et al.  A single atom transistor , 2012, 2012 IEEE Silicon Nanoelectronics Workshop (SNW).

[3]  Paul S. Peercy,et al.  The drive to miniaturization , 2000, Nature.

[4]  L. Oberbeck,et al.  The use of etched registration markers to make four-terminal electrical contacts to STM-patterned nanostructures , 2005, Nanotechnology.

[5]  M. Simmons,et al.  Use of a scanning electron microscope to pattern large areas of a hydrogen resist for electrical contacts , 2007 .

[6]  A. G. Fowler,et al.  Two-dimensional architectures for donor-based quantum computing , 2006 .

[7]  D. J. Carter,et al.  Phosphorus δ-doped silicon: mixed-atom pseudopotentials and dopant disorder effects , 2011, Nanotechnology.

[8]  B. E. Kane.  A silicon-based nuclear spin quantum computer , 1998, Nature.

[9]  H. Tsai,et al.  Comparison of thermal reactions of phosphine on Ge(1 0 0) and Si(1 0 0) by high-resolution core-level photoemission , 2001 .

[10]  Kevin C. Prince,et al.  SPELEEM: Combining LEEM and Spectroscopic Imaging , 1998 .

[11]  Michelle Y. Simmons,et al.  Thermal dissociation and desorption of PH3 on Si(001): A reinterpretation of spectroscopic data , 2006 .

[12]  L. Oberbeck,et al.  Scanning probe microscopy for silicon device fabrication , 2005 .

[13]  Andreas Fuhrer,et al.  Optimizing dopant activation in Si:P double δ-layers , 2010 .

[14]  M. Simmons,et al.  Low resistivity, super-saturation phosphorus-in-silicon monolayer doping , 2014 .

[15]  N. Tolk,et al.  Absolute total cross sections for electron-stimulated desorption of hydrogen and deuterium from silicon(111) measured by second harmonic generation , 2000 .

[16]  Michelle Y. Simmons,et al.  Toward Atomic-Scale Device Fabrication in Silicon Using Scanning Probe Microscopy , 2004 .

[17]  H. Duan,et al.  Resolution limits of electron-beam lithography toward the atomic scale. , 2013, Nano letters (Print).

[18]  F. G. Allen,et al.  Work Function, Photoelectric Threshold, and Surface States of Atomically Clean Silicon , 1962 .

[19]  R. Rahman,et al.  Spin readout and addressability of phosphorus-donor clusters in silicon , 2012, Nature Communications.

[20]  E. Bauer,et al.  Surface studies by low-energy electron microscopy (LEEM) and conventional UV photoemission electron microscopy (PEEM) , 1989 .

[21]  M. Simmons,et al.  Disentangling phonon and impurity interactions in δ-doped Si(001) , 2014 .

[22]  L. Oberbeck,et al.  Effective removal of hydrogen resists used to pattern devices in silicon using scanning tunneling microscopy , 2005 .

[23]  D. J. Carter,et al.  Determining the electronic confinement of a subsurface metallic state. , 2014, ACS nano.

[24]  D. Lin,et al.  Interaction of phosphine with Si(100) from core-level photoemission and real-time scanning tunneling microscopy , 2000 .

[25]  Michelle Simmons,et al.  Exploring the limits of N-type ultra-shallow junction formation. , 2013, ACS nano.

[26]  D. Lin,et al.  Thermal reactions of phosphine with Si(100): a combined photoemission and scanning-tunneling-microscopy study , 1999 .

[27]  D. J. Carter,et al.  Valley splitting in a silicon quantum device platform. , 2014, Nano letters.

[28]  Michelle Y. Simmons,et al.  A surface code quantum computer in silicon , 2015, Science Advances.

[29]  K. Oura,et al.  Electron-stimulated desorption of hydrogen from H/Si(001)-1×1 surface studied by time-of-flight elastic recoil detection analysis , 1999 .

[30]  P. Feibelman,et al.  Ion desorption by core-hole Auger decay , 1978 .

[31]  L. Oberbeck,et al.  Influence of doping density on electronic transport in degenerate Si:Pδ-doped layers , 2006 .

[32]  D. E. Jesson,et al.  Surface Electron Microscopy of Ga Droplet Dynamics on GaAs (001) , 2010 .

[33]  L. Hollenberg,et al.  Single-shot readout of an electron spin in silicon , 2010, Nature.

[34]  M. Simmons,et al.  The Impact of Dopant Segregation on the Maximum Carrier Density in Si:P Multilayers. , 2015, ACS nano.

[35]  M. Simmons,et al.  Microscopic four-point-probe resistivity measurements of shallow, high density doping layers in silicon , 2012 .

[36]  ERIC M. VOGEL,et al.  Technology and metrology of new electronic materials and devices. , 2007, Nature nanotechnology.

[37]  Gerhard Klimeck,et al.  Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting , 2013, Nature Communications.