Search Results

Now showing 1 - 3 of 3

Some of the metrics are blocked by your
consent settings
Fabrication of mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunction photodiodes by liftoff technique combined with photolithography
(2013-12-01)
Funasaki, Suguru
;
Promros, Nathaporn
;
Iwasaki, Ryuhei
;
Takahara, Motoki
;
Shaban, Mahmoud
Mesa structural n-type nanocrystalline (NC) FeSi<inf>2</inf>/p-type Si heterojunctions were fabricated by a liftoff technique combined with photolithography in order to improve the diode performance, particularly to reduce the parasitic capacitance. Their current-voltage characteristics were experimentally studied in the dark and under illumination using a 1.31 μm laser at room temperature. Their junction capacitance density and leakage current density were evidently reduced as compared with those of the normal structural diodes. The mesa diode exhibits a good rectifying action with a rectification ratio of approximately three orders of magnitude at bias voltages of ±1 V. The photodetection was clearly observed owing to the suppression in the dark current. The estimated detectivity is 2.0 × 109 cm√Hz/W at zero bias, which is an order of magnitude larger than that of the normal structural diodes. This should be because the formation of interface states is reduced accompanied by the interface area reduction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Some of the metrics are blocked by your
consent settings
Characterizations of mesa structural near-infrared n-type nanocrystalline-FeSi2/p-type si heterojunction photodiodes at low temperatures
(2013-10-04)
Promros, Nathaporn
;
Iwasaki, Ryuhei
;
Funasaki, Suguru
;
Yamashita, Kyohei
;
Yoshitake, Tsuyoshi
In order to reduce the parasitic capacitance, mesa structural n-type NC-FeSi<inf>2</inf>/p-type Si heterojunctions were fabricated by photolithography. Their current-voltage characteristics were measured in the dark and under illumination using a 1.31 μm laser in the temperature range of 60 - 300 K. Their junction capacitance density was evidently reduced as compared with that of the normal structural diodes. The dark current was markedly reduced with a decrease in the temperature. At 60 K, a rectifying current ratio in the dark became more than five orders of magnitude at ±1V. The ratio of the photocurrent to the dark current was dramatically enhanced to be approximately two orders of magnitude, and the detectivity was calculated to be 1.5 × 1011 cmHz1/2/W at -1V. The obtained results showed a remarkable improvement in the device performance as compared with those at 300 K. © (2013) Trans Tech Publications, Switzerland.
Some of the metrics are blocked by your
consent settings
Effect of exposure energy, focus range, and surface reflection on the photolithography process of contact hole patterning
(2008-10-07)
Sonboonton, R.
;
Chaowicharat, E.
;
Meesapawong, P.
;
Ladthidej, J.
;
Titiroongruang, W.
The patterning the contact holes by photolithography process, in this case polysilicon contacts, is the process to produce electrical connection between metal layer and polysilicon gates or metal layer and source/drain. The photolithography process can control size and shape of the contact hole patterns on photoresist before permanently patterned by etching process and then metallization. The contact holes were specified to have the size of 0.8 micron after the photolithography process. In order to achieve this, the process parameters to be considered are exposure energy, focus length of the lens system, and the effect of light reflecting from the film topography underneath. Since in the previous processing step, the attempt to reduce the film topography was done by planarization using BPSG. By adjusting the exposure energy and focus, the optimal condition, to produce 0.8 micron contact holes, was found to be energy of 305 mJ/cm and focus of-1.0 μm. © 2008 IEEE.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results