Letter | Published:

Enhancing semiconductor device performance using ordered dopant arrays


As the size of semiconductor devices continues to shrink, the normally random distribution of the individual dopant atoms within the semiconductor becomes a critical factor in determining device performance—homogeneity can no longer be assumed1,2,3,4,5. Here we report the fabrication of semiconductor devices in which both the number and position of the dopant atoms are precisely controlled. To achieve this, we make use of a recently developed single-ion implantation technique6,7,8,9, which enables us to implant dopant ions one-by-one into a fine semiconductor region until the desired number is reached. Electrical measurements of the resulting transistors reveal that device-to-device fluctuations in the threshold voltage (Vth; the turn-on voltage of the device) are less for those structures with ordered dopant arrays than for those with conventional random doping. We also find that the devices with ordered dopant arrays exhibit a shift in Vth, relative to the undoped semiconductor, that is twice that for a random dopant distribution (- 0.4 V versus -0.2 V); we attribute this to the uniformity of electrostatic potential in the conducting channel region due to the ordered distribution of dopant atoms. Our results therefore serve to highlight the improvements in device performance that can be achieved through atomic-scale control of the doping process. Furthermore, ordered dopant arrays of this type may enhance the prospects for realizing silicon-based solid-state quantum computers10.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Keyes, R. W. The effect of randomness in the distribution of impurity atoms on FET thresholds. Appl. Phys. 8, 251–259 (1975)

  2. 2

    Mizuno, T., Okamura, J. & Toriumi, A. Experimental–study of threshold voltage fluctuation due to statistical variation of channel dopant number in MOSFET. IEEE Trans. Electron Devices 41, 2216–2221 (1994)

  3. 3

    Wong, H. S. & Taur, Y. Discrete dopant distribution effects in nanometer-scale MOSFETs. Microelectron. Reliab. 38, 1447–1456 (1998)

  4. 4

    Sano, N. & Tomizawa, M. Random dopant model for three-dimensional drift-diffusion simulations in metal-oxide-semiconductor field-effect-transistors. Appl. Phys. Lett. 79, 2267–2269 (2001)

  5. 5

    Ebert, Ph., Jager, N. D., Urban, K. & Weber, E. R. Nanoscale fluctuations in the distribution of dopant atoms: Dopant-induced dots and roughness of electronic interfaces. J. Vac. Sci. Technol. B 22, 2018–2025 (2004)

  6. 6

    Ohdomari, I. in Proc. 1st Int. Symp. Control of Semiconductor Interfaces (eds Ohdomari, I., Oshima, M. & Hiraki, A.) 223–240 (North-Holland, Amsterdam, 1994)

  7. 7

    Matsukawa, T. et al. Development of single-ion implantation—Controllability of implanted ion number. Appl. Surf. Sci. 117/118, 677–683 (1997)

  8. 8

    Shinada, T., Ishikawa, A., Hinoshita, C., Koh, M. & Ohdomari, I. Reduction of fluctuation in semiconductor conductivity by one-by-one ion implantation of dopant atoms. Jpn J. Appl. Phys. 39, L265–L268 (2000)

  9. 9

    Shinada, T., Koyama, H., Hinoshita, C., Imamura, K. & Ohdomari, I. Improvement of focused ion-beam optics in single-ion implantation for higher aiming precision of one-by-one doping of impurity atoms into nano-scale semiconductor devices. Jpn. J. Appl. Phys. 41, L287–L290 (2002)

  10. 10

    Kane, B. E. A silicon-based nuclear spin quantum computer. Nature 393, 133–137 (1998)

  11. 11

    Sze, S. M. Physics of Semiconductor Devices: Physics and Technology 2nd edn (Wiley, New York, 2001)

Download references


This work was partly supported by the Special Coordination Funds for Promoting Science and Technology, Center of Excellence (COE) research programme and the 21st-century Center of Excellence (21COE) programme from the Ministry of Education, Culture, Sports, Science and Technology, Japan. We thank Y. Shinoda for his critical reading of the manuscript. Author Contributions The experiment was planned by T.S. Samples were prepared, and their electrical properties measured, by T.S., S.O. and T.K. SII was invented by I.O.

Author information

Correspondence to Takahiro Shinada.

Ethics declarations

Competing interests

Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Further reading

Figure 1: Experimental device and results of single ion implantation.
Figure 2: Typical electrical characteristics.
Figure 3: Calculated potential distribution of the channel region.
Figure 4: Histograms of V th shift (Δ V th ) before and after single-ion implantation from 10 resistors.


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.