Browsing by Author "CHEN, YE"

Now showing 1 - 3 of 3

ENERGY-DEPENDENCE OF THE ELECTRON-CAPTURE CROSS-SECTION OF GAP STATES IN UNDOPED A-SI-H FILMS
(1995-02-15)
CHEN, YE
;
WANG, FS
;
TSAI, JW
;
CHENG, HC
;
電子工程學系及電子研究所
Isothermal capacitance transient spectroscopy (ICTS) has been employed to measure the energy dependence of the electron-capture cross section of continuously distributed defect levels in undoped a-Si:H film for the first time, via the proposed novel structure. For undoped a-Si:H films! experimental results show that the electron-capture cross section of defect levels initially decreases exponentially, reaches a minimum, and then increases exponentially with energy depth measured from the mobility edge of the conduction band. This v-shaped distribution of the electron-capture cross section of continuously distributed defect levels in undoped a-Si:H film is different from that in phosphorous-doped a-Si:H film. This means that mechanisms other than multiphonon emission can be dominant in the electron-capture process in the gap states in undoped a-Si:H film.
NOVEL PHENOMENON OF THE AL-1 WT-PERCENT-SI CONTACTS ON THE NF3/AR POST-ETCHING-TREATED N-SI SUBSTRATES
(1993-09-15)
CHENG, HC
;
CHEN, YE
;
JUANG, MH
;
YEN, PW
;
LIN, L
Post-etching treatment (PET) using an in situ NF3/Ar low-energy plasma was reported to be efficient in removing the residual layer and defects caused by reactive ion etching (RIE) as well as producing a clean surface conventionally believed suitable for electrical contacts. However, the PET process was found to increase the contact resistance between Al-1 wt%Si and n+-Si substrate for the first time. It is attributed to the formation of p-type-like Si epitaxy on the n+-Si substrate and the lower effective surface donor concentration.
NOVEL STRUCTURE FOR MEASURING THE DENSITY-OF-STATE DISTRIBUTION OF HIGH-RESISTIVITY SEMICONDUCTOR-FILMS BY ISOTHERMAL CAPACITANCE TRANSIENT SPECTROSCOPY
(1994-12-01)
CHEN, YE
;
WANG, FS
;
TSAI, JW
;
CHENG, HC
;
電子工程學系及電子研究所
A novel structure, metal/high-resistivity semiconductor (HRS)/n-type c-Si substrate with the space charge region (SCR) entirely covering the HRS film and penetrating into the c-Si substrate, has been proposed for determining the density-of-state distribution g(E) of the HRS films via the isothermal capacitance transient spectroscopy (ICTS) method. The structure has been tested and applied to the measurement of g(E) of the undoped hydrogenated amorphous silicon (a-Si:H) film. For undoped a-Si:H film with optical gap E(o) = 1.72 eV, a peak in g(E) is observed at 0.66 eV below the conduction band mobility edge E(c), with the attempt-to-escape frequency of u(n) = 1.61 x 10(13) s(-1). These midgap states are surmised to be correlated with the doubly occupied dangling bond D-.