Low Specific On-resistance SOI LDMOS Device with P⁺P-top Layer in the Drift Region

Abstract

Abstract-In this paper, a novel low specific onresistance SOI LDMOS Device with P+P-top layer in the drift region is proposed and investigated using a two dimensional device simulator, MEDICI. The structure is characterized by a heavily-doped P + region which is connected to the P-top layer in the drift region. The P + region can modulates the surface electric field profile, increases the drift doping concentration and reduces the sensitivity of the breakdown voltage on the geometry parameters. Compared to the conventional D-RESURF device, a 25.8% decrease in specific on-resistance and a 48.2% increase in figure of merit can be obtained in the novel device. Furthermore, the novel P + P-top device also present cost efficiency due to the fact that the P + region can be fabricated together with the P-type body contact region without any additional mask.

Problems of Designing LDMOS-Transistors Working at Increased Supply Voltage

“…The analysis of the known constructions of the highvoltage MOS transistors considered in [1][2][3] showed that the construction of the so-called LDMOS transistor is most suitable for the existing process flow. Its characteristic design feature is the existence of an extended weakly-doped area which adjoins the drain region, which is called DRIFT-region that allows to create an impurity depletion zone on which length there is a uniform voltage drop (figure 1) at the expense of small extent of alloying.…”

Problems of Designing LDMOS-transistors Working at Increased Supply Voltage

“…Анализ существующих конструкций высоковольтных МОП-транзисторов, рассмотренных в [1][2][3], показал, что для существующего технологического маршрута в наибольшей степени подходит конструкция так называемого LDMOS-транзистора. Его характерной конструктивной особенностью является наличие протяженной слаболегированной области, примыкающей к области стока и называемой DRIFT-областью, что позволяет за счет малой степени ее легирования создать зону обеднения примеси, на длине которой происходит равномерное падение напряжения (рис.…”