Báo cáo hóa học: Memory properties and charge effect study in Si nanocrystals by scanning capacitance microscopy and spectroscopy

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Memory properties and charge effect study in Si nanocrystals by scanning capacitance microscopy and spectroscopy
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Báo cáo hóa học: " Memory properties and charge effect study in Si nanocrystals by scanning capacitance microscopy and spectroscopy"Lin et al. Nanoscale Research Letters 2011, 6:163http://www.nanoscalereslett.com/content/6/1/163 NANO EXPRESS Open AccessMemory properties and charge effect study in Sinanocrystals by scanning capacitance microscopyand spectroscopyZhen Lin1*, Georges Bremond1†, Franck Bassani2† Abstract In this letter, isolated Si nanocrystal has been formed by dewetting process with a thin silicon dioxide layer on top. Scanning capacitance microscopy and spectroscopy were used to study the memory properties and charge effect in the Si nanocrystal in ambient temperature. The retention time of trapped charges injected by different direct current (DC) bias were evaluated and compared. By ramp process, strong hysteresis window was observed. The DC spectra curve shift direction and distance was observed differently for quantitative measurements. Holes or electrons can be separately injected into these Si-ncs and the capacitance changes caused by these trapped charges can be easily detected by scanning capacitance microscopy/spectroscopy at the nanometer scale. This study is very useful for nanocrystal charge trap memory application. IBM, 1982 (Nobel Prize awards in 1986), it has becomeRecently, the self-assembled silicon nanocrystals (Si-ncs) a powerful high-spatial-resolution tool for nanoscalethat are formed within ultrathin SiO2 layer are consid- semiconductor analysis or characterization comparing toered to be a promising replacement of this conventional several conventional methods for such as x-ray, nuclear,floating gate [1,2]. These isolated Si-ncs embedded in electron and ion beam, optical and infrared and chemi-between a tunnel and a top dielectric layer serve as the cal technique. It can provide simultaneous topographycharge storage nodes and exhibit many physical proper- and various physical feature images with some addi-ties even at room temperature such as Coulomb block- tional electrical applications such as scanning capaci-ade [3], single-electron transfer [4] and quantization tance microscopy (SCM) [6,7], electrostatic forcecharges effect [5] which differ from bulk crystals. It can microscopy (EFM) [8], scanning resistance microscopyreduce the problem of charge loss encountered in con- [9] and Kelvin probe force microscopy [10]. In amountventional memories, cause thinner injection oxides and of these techniques, SCM became one of the most use-hence smaller operating voltages, better endurance and ful methods for the capacitance characterization offaster write/erase speeds. So, the characterisation and semiconductor as its non-destructive detection of variesunderstanding of its charging mechanism in such nanos- electrical properties with high resolution such as dopanttructure is of prime importance. profiling variation [11], silicon p-n junction [12] and Although the conventional I-V and C-V characteriza- carrier injection [13], etc.tion methods for memory application provide a vast In this letter, scanning capacitance microscopy andamount of macro information, these methods lack the ...