메뉴 건너뛰기
Nano Letters
Volumn 6, Issue 12, 2006, Pages 2929-2934
Single p-type/intrinsic/n-type silicon nanowires as nanoscale avalanche photodetectors
Author keywords

[No Author keywords available]
Indexed keywords

AVALANCHE PHOTODETECTORS; DIBORANE; DOPANTS; SILICON NANOWIRES;
EID: 33846356750     PISSN: 15306984     EISSN: None     Source Type: Journal    
DOI: 10.1021/nl062314b     Document Type: Article
Times cited : (262)
References (49)
  • 2
    • 33846359905 scopus 로고    scopus 로고
    • (b) Yang, P. MRS Bull. 2005, 50, 85.
    • (2005) MRS Bull , vol.50 , pp. 85
    • Yang, P.1
  • 30
    • 33846360250 scopus 로고    scopus 로고
    • 4 = 1:100. Effective carrier concentrations were estimated based on four probe transport measurements at room temperature.
    • 4 = 1:100. Effective carrier concentrations were estimated based on four probe transport measurements at room temperature.
  • 33
    • 9444287420 scopus 로고    scopus 로고
    • Capasso, F. The Physics of Avalanche Photodiodes. In Tsang, W. T. Semiconductors and Semimetals, 22., Part D.; Willardson, R. K., Beers, A. C., Eds.; Academic Press: Orlando, FL, 1985.
    • Capasso, F. The Physics of Avalanche Photodiodes. In Tsang, W. T. Semiconductors and Semimetals, Vol. 22., Part D.; Willardson, R. K., Beers, A. C., Eds.; Academic Press: Orlando, FL, 1985.
  • 37
    • 33846371096 scopus 로고    scopus 로고
    • All p-i-n devices were fabricated on heavily doped Si substrates with 50-nm thermal oxide (n-type, resistivity <0.005 Ω-cm, Nova Electronic Materials, Carrollton, TX, Nickel contacts (60 nm thick) at the p- and n-type ends of individual SiNWs were patterned by electron beam lithography and deposited by thermal evaporation. The contacts were annealed at 350°C for 30 s. EFM and SGM measurements were carried out with a Nanoscope Ilia and metal-coated tips (Nanosensor) with radii of curvature of 10-30 nm. EFM and SGM data were acquired in lift mode (lift height, 150 and 15 nm for EFM and SGM, respectively) with Vsd, 1 V and Vtip, 9 V. In EFM measurements, the electrostatic force between the nanowire and the AFM tip results in a phase shift. Δφ ∝ (d2C/dz 2)(Vtip, Φ -Vsd)2, where C is the tip-sample capacitance, z is the tip-sample separation, and Φ is the work function diffe
    • 18,24
  • 38
    • 33846362476 scopus 로고    scopus 로고
    • The 488 nm excitation beam of an Ar-ion laser, focused to a diffraction-limited focal spot by a 0.9-NA objective microscope, is used to locally photoexcite the p-i-n SiNW. When the p-i-n SiNW is operated at reverse bias, a photocurrent is detected when the laser impinges on the p-i-n SiNW. The piezo-controlled sample stage (Digital PI PZT flexure stage) is then used to scan the sample from point to point to spatially map out the photocurrent. The current was measured in the dark and under dc illumination conditions using a parameter analyzer (Agilent 4156c). The incident optical power level was kept large enough to ensure that the dark current is negligible compared to the photocurrent in the bias range of the experiments.
    • The 488 nm excitation beam of an Ar-ion laser, focused to a diffraction-limited focal spot by a 0.9-NA objective microscope, is used to locally photoexcite the p-i-n SiNW. When the p-i-n SiNW is operated at reverse bias, a photocurrent is detected when the laser impinges on the p-i-n SiNW. The piezo-controlled sample stage (Digital PI PZT flexure stage) is then used to scan the sample from point to point to spatially map out the photocurrent. The current was measured in the dark and under dc illumination conditions using a parameter analyzer (Agilent 4156c). The incident optical power level was kept large enough to ensure that the dark current is negligible compared to the photocurrent in the bias range of the experiments.
  • 41
    • 33846353113 scopus 로고    scopus 로고
    • Local photoexcitation of either the p- or n-regions, which enables minority carrier injection of electrons and holes, respectively, into the i-region, was carried out using a diffraction limited laser spot with a fwhm of ca. 500 nm. Furthermore, to prevent direct photoexcitation of the i-region, we lithographically masked this section of the sample with a high optical density polymer (PSK2000. Brewer Science, Inc.); the 1.5 μm thickness used has a 99.9% absorption at the excitation wavelength. 488 nm, used in our experiments.
    • Local photoexcitation of either the p- or n-regions, which enables minority carrier injection of electrons and holes, respectively, into the i-region, was carried out using a diffraction limited laser spot with a fwhm of ca. 500 nm. Furthermore, to prevent direct photoexcitation of the i-region, we lithographically masked this section of the sample with a high optical density polymer (PSK2000. Brewer Science, Inc.); the 1.5 μm thickness used has a 99.9% absorption at the excitation wavelength. 488 nm, used in our experiments.
  • 42
    • 33846358084 scopus 로고    scopus 로고
    • Careful comparison of the p-i-n SiNW devices shown in Figures 3b and 4c shows some difference in the reverse bias characteristics. In Figure 3b, we observe an essentially constant Idark vs bias up to the onset of avalanche multiplication. This behavior is expected for an ideal p-i-n device. The device shown in Figure 4c shows, however, a small increase in I dark vs revserse bias before the gain onset is reached. It is an interesting question to explore if this breakdown voltage might be limited by a microplasma mechanism, since in the SiNW devices the field is by design localized to a nanoscale size spot 20 nm diameter, Microplasma breakdown can occur in localized spots in avalanche devices, as opposed to bulk breakdown, which occurs at higher bias in silicon.15 Overall these data are consistent with the expected behavior of bulk p-i-n Si devices, although future more detailed studies might reveal interesting differences
    • 15 Overall these data are consistent with the expected behavior of bulk p-i-n Si devices, although future more detailed studies might reveal interesting differences.

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.