Hot-Carrier-Induced Photon Emission in Thin SOI/MOSFETs

Seiichiro KAWAMURA

IEICE TRANSACTIONS on Electronics   Vol.E75-C    No.12    pp.1471-1476
Publication Date: 1992/12/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on SOI (Si on Insulator) Devices)
Category: Hot Carrier
hot-carrier,  photon emission,  thin SOI,  carrier temperature,  

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A study of hot-carrier-induced photon emission in thin SOI/MOSFETs has been carried out both for bonded-SOI and SIMOX/SOI. The photon emission is observed not only in the drain region but also in the source region for SOI/MOSFETs, whereas only in the drain region for conventional bulk MOSFETs. From the emission spectrum, it can be concluded that the emission mechanism of the source region is probably a photon-assisted direct recombination of electrons and holes, while both the recombination and Bremsstrahlung are the possible mechanism for the drain region. The total photo intensity from SOI/MOSFETs increases as the SOI film thickness decreases, showing that strong impact ionization occurs near the drain region for thinner SOI devices. The relation between the lifetime and the photo intensity for SOI/MOSFETs is very similar to that between the lifetime and the substrate current for conventional bulk/MOSFETs, proving that photon emission is a good indicator of the hot carrier degradation in thin SOI/MOSFETs. The lifetime measurement using the photon emission both for SOI and bulk devices indicates that longer lifetime can be expected for thin film SOI/MOSFETs with a reduced drain bias which will be indispensable for future sub-half micron MOSFETs.