Skip to main content Accessibility help
×
Home
Hostname: page-component-747cfc64b6-dwt4q Total loading time: 0.256 Render date: 2021-06-14T13:04:56.875Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": true, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true }

Analysis of Drain Currents During Switching off a-Si:H Based Thin Film Transistors

Published online by Cambridge University Press:  10 February 2011

F. Lemmi
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA,94304
R. A. Street
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA,94304
Get access

Abstract

We present measurements and analysis of a-Si:H thin film transistor (TFT) transients when the gate voltage switches the device from a conducting to a non-conducting state. The drain current transient has been monitored in the medium-long (Ims-100s) time range and exhibits a power law decay extending to at least 10 seconds. The decay has been studied over a range of drain voltages and gate off-state voltages. Measured data show that the gate off-state can help to obtain a low drain leakage current at long times when high drain voltages are being used.

However, the decay at low drain voltages shows little sensitivity to different gate off-state voltages. An analytical model is developed, based on the relaxation of the Fermi level toward mid-gap in a spatially uniform TFT channel. The model shows how deep defects are responsible for the current decay slope at long times, while shallower states determine the slope in the short time range. An energy-independent defect density would produce a 1/t slope for the current decay. Shallow states and deep states affect in opposite ways the slope since their density is energydependent in opposite ways as Fermi level moves deeper into the band-gap. Furthermore, long decay times are associated with a wider depletion region in the channel and increase the total number of defect states involved. A steeper decay than 1/t is expected and observed for shorttime ranges, while a more gradual (about 1/t 1/2) one corresponds to long time measurements. The implications of the transient decay for the performance of active matrix arrays will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below.

References

1 Ibaraki, N., MRS Symp. Proc., 336, p. 749 (1994).CrossRefGoogle Scholar
2 Street, R.A., Wu, X.D., Weisfield, R., Ready, S., Apte, R., Nguyen, M., Nylen, P., MRS Symp. Proc., 377, p. 757 (1995).CrossRefGoogle Scholar
3 Antonuk, L.E., El-Mohri, Y., Huang, W., Siewerdsen, J., J, Yorkston, Street, R.A., MRS Symp. Proc. 336, p. 855 (1994).CrossRefGoogle Scholar
4 Hack, M., Weisfield, R., Wilums, M.F., Masterton, G.H., LeComber, P.G., MRS Symp. Proc., 297 p. 865 (1993).CrossRefGoogle Scholar
5 Shur, M.S., Jacunski, M.D., Slade, H.C., Owusu, A.A., Ytterdal, T., Hack, M., Proceedings of the Third Symposium on Thin Film Transistor Technologies, 96–23, p. 242 (1996).Google Scholar
6 Street, R.A., Weisfield, R.L., Apte, R.B., Ready, S.E., Moore, A., Nguyen, M., Jackson, W.B., Nylen, P., Thin Solid Films 296, p. 172 (1997).CrossRefGoogle Scholar
7 Street, R.A., Philos. Mag. B, 63 (6), p. 1343 (1991).CrossRefGoogle Scholar
8 Shur, M., Hack, M., J. Appl. Phys., 55 (10), p. 3831 (1984).CrossRefGoogle Scholar

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Analysis of Drain Currents During Switching off a-Si:H Based Thin Film Transistors
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Analysis of Drain Currents During Switching off a-Si:H Based Thin Film Transistors
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Analysis of Drain Currents During Switching off a-Si:H Based Thin Film Transistors
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *