• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.254-259
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• 2015

This paper reports the optimized mixed-signal performance of a high-voltage (HV) laterally double-diffused metaloxide-semiconductor (LDMOS) field-effect transistor (FET) with a dual gate oxide (DGOX). The fabricated device is based on the split-gate FET concept. In addition, the gate oxide on the source-side channel is thicker than that on the drain-side channel. The experiment results showed that the electrical characteristics are strongly dependent on the source-side channel length with a thick gate oxide. The digital and analog performances according to the source-side channel length of the DGOX LDMOS device were examined for circuit applications. The HV DGOX device with various source-side channel lengths showed reduced by maximum 37% on-resistance (R_ON) and 50% drain conductance (g_ds). Therefore, the optimized mixed-signal performance of the HV DGOX device can be obtained when the source-side channel length with a thick gate oxide is shorter than half of the channel length.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.223-226
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• 2003

We propose an improvement method for a $\underline{G}ate$ $\underline{OX}ide(GOX)$ thinning at the edge of $\underline{S}hallow$ $\underline{T}rench$ $\underline{I}solation(STI)$, when STI is adopted to Dual Gate Oxide(DGOX) Process. In the case of SOC(System On-a-Chip), the DGOX process is usually used for realizing both a low and a high voltage parts in one chip. However, it is found that the severe GOX thinning occurs from at STI top edge region and a dent profile exists at the top edge of STI, when conventional DGOX and STI process carried out in high density device chip. In order to overcome this problem, a new DGOX process is tried in this study. And we are able to prevent the GOX thinning by H2 anneal, partially SiN liner skip, and a method which is merged a thick sidewall oxide(S/O) with a SiN pull-back process. Therefore, a good subthreshold characteristics without a double hump is obtained by the prevention of a GOX thinning and a deep dent profile.