Channel length modulation

About: Channel length modulation is a research topic. Over the lifetime, 1790 publications have been published within this topic receiving 34179 citations.

A compact drain current model of short-channel cylindrical gate-all-around MOSFETs

Abstract: A fully analytical potential model, valid in the weak inversion regime of short-channel cylindrical gate-all-around (GAA) MOSFET, is proposed. The model derivation is based on a previous analytical expression for tetragonal GAA MOSFET and the rotational symmetry of the tetragonal cross section. Device simulations were performed to verify that the potential distribution along the channel is properly described in all positions within the silicon body. Using the potential model, analytical expressions for the threshold voltage, subthreshold swing and drain-induced barrier lowering have been derived. Including the short-channel effects within an existing model for the subthreshold leakage current and an analytical drain current model of long-channel devices in strong inversion, a compact drain current model has been derived describing with good accuracy the transfer and output characteristics of short-channel GAA MOSFETs in all regions of operation.

Compounded power MOSFET

Abstract: Provided is a compounded power MOSFET which has a high positive and negative withstand voltages for the drain terminal relative to the source terminal, and can be formed on a single chip based on the conventional fabrication process of power MOSFETs. Power MOSFETs 10 and 11 have their drains connected together, the MOSFET 10 has its source and gate used for the source terminal 0 and gate terminal 1, respectively, of the compounded power MOSFET 60, and the MOSFET 11 has its source used for the drain terminal 2. The compounded power MOSFET includes a voltage comparator 50 which drives the MOSFET 11 to turn off when the terminal 2 has a negative voltage, and a voltage transmitter 51 which is connected between the terminal 1 and the gate of the MOSFET 11 to block a current flowing from the terminal 2 to the terminal 1 by way of the circuit 50 and transfer the voltage of the terminal 1 to the gate of the MOSFET 11. The positive withstand voltage is provided by the MOSFET 10, and the negative withstand voltage is provided by the MOSFET 11.

MOSFET bias dependent series resistance extraction from RF measurements

Abstract: A simple technique to determine MOSFET gate-bias dependent source and drain series resistances from experimental S-parameters is presented. This technique uses the measured data of a single device. The extracted data allow the accurate modelling of the bias dependence of the output resistance of the MOSFET up to 27 GHz.

Asymmetrical MOS channel structure with drain extension

Abstract: A method of forming a MOS transistor without a lightly doped drain (LDD) region between the channel region and drain is provided. The channel region and a drain extension are formed from two separate tilted ion implantation processes, after the deposition of the gate electrode. The tilted implantation forms a relatively short channel length, with respect to the length of the gate electrode. The position of the channel is offset, and directly adjoins the source. A second tilted implant process forms a drain extension region under the gate electrode, adjacent the drain. Elimination of LDD areas reduces the number of masking and doping steps required to manufacture a transistor. Further, the drain extension area promotes transistor performance, by eliminating source resistance. At the same time, sufficient doping of the drain extension area insures that the drain resistance through the drain extension remains low. This drain extension acts to more evenly distribute electric fields so that large breakdown voltages are possible. In this manner, larger I d currents and faster switching speeds are obtained. A MOS transistor having a short, offset channel and drain extension formed through dual tilted ion implants is also provided.