A Study on Hot-Carrier-Induced Photoemission in n-MOSFETs

Toshihiro MATSUDA  Naoko MATSUYAMA  Kiyomi HOSOI  Etsumasa KAMEDA  Takashi OHZONE  

IEICE TRANSACTIONS on Electronics   Vol.E82-C   No.4   pp.593-601
Publication Date: 1999/04/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Microelectronic Test Structures)
MOSFET,  hot carriers,  photoemission,  junction breakdown,  

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Profiles of photoemission induced by hot electrons in LDD-type n-MOSFETs with L = 0.35-2.0 µm were measured with a photoemission microscope, which had a capability of 1000 magnification and a spatial resolution of 27 nm/pixel on a CCD imager sufficient to detect profile changes in the channel length direction. Under the bias condition of maximum substrate current, photoemission peaks were located at the LDD-drain edge and the n+-drain edge for the devices with L = 0.35 and L 0.40 µm, respectively. A peak position, only in the case of the 0.35 µm device, shifted toward the drain side by about 80 nm at VD = 7.0 V. Since VD did not affect peak positions in L 0.40 µm devices, the photoemission mechanisms may be different between L = 0.35 µm and L 0.40 µm devices. The photoemission points due to p-n junction breakdown were located at the cylindrical curvature edge of the n+-drain region. Two-dimensional device simulation, even when the lateral electric field, electron temperature and radiative recombination rate were taken into account, could not explain the experimental results completely.