Comparison of GaP and PH3 as dopant sources for STM-based device fabrication

We present a comparative study of the use of a GaP solid source as an alternative to gaseous PH3 for controlled phosphorus δ-doping of lithographic patterns on H:Si(001) fabricated by scanning tunnelling microscopy (STM). Whilst our electrical studies show that P δ-doping of Si with the GaP solid source and gaseous PH3 result in essentially the same electrical characteristics, our STM studies reveal that P2 molecules from the GaP source exhibit a lower selectivity between bare Si(001) and H:Si(001) compared to PH3 molecules. We discuss the significance of our findings in the context of fabricating nanoscale P dopant devices in Si using STM-based lithography.

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

[2]  J. Tucker,et al.  Nanoscale electronics based on two-dimensional dopant patterns in silicon , 2004 .

[3]  L. Oberbeck,et al.  Effect of encapsulation temperature on Si:P δ-doped layers , 2004 .

[4]  S. R. Schofield,et al.  Phosphine dissociation on the Si(001) surface. , 2004, Physical review letters.

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

[6]  S. R. Schofield,et al.  Atomically precise placement of single dopants in si. , 2003, Physical review letters.

[7]  S. R. Schofield,et al.  Encapsulation of phosphorus dopants in silicon for the fabrication of a quantum computer , 2002, cond-mat/0208355.

[8]  S. R. Schofield,et al.  Towards the fabrication of phosphorus qubits for a silicon quantum computer , 2001, cond-mat/0104569.

[9]  K. Oura,et al.  Hydrogen interaction with clean and modified silicon surfaces , 1999 .

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

[11]  J. Tucker,et al.  Prospects for atomically ordered device structures based on STM lithography , 1998 .

[12]  K. Eberl,et al.  Electronic properties of InGaP grown by solid‐source molecular‐beam epitaxy with a GaP decomposition source , 1994 .

[13]  R. Hamers,et al.  Direct dimer‐by‐dimer identification of clean and monohydride dimers on the Si(001) surface by scanning tunneling microscopy , 1994 .

[14]  M. Lagally,et al.  Scanning tunneling microscopy studies of structural disorder and steps on Si surfaces , 1989 .

[15]  H. Kroemer,et al.  A GaP decomposition source for producing a dimer phosphorus molecular beam free of gallium and tetramer phosphorus , 1985 .