Research And Implementation Of Wideband High Resolution Frequency Synthesizer

In RF power devices,LDMOS exhibits superior electrical characteristics such as high gain,and other electrical characteristics compared to other power devices.The advantages make LDMOS become a research hotspot in the field of RF power devices.As the feature size of transistors continues to decrease,the integration of power integrated circuits continue to increase,and the requirements of RF power devices is becoming more and more demanding.Therefore,some researchers proposed to introduce the strain technology into the power integrated circuit.In integrated circuits with PMOS devices,PMOS is a bottleneck that limits the performance of integrated circuits,which is also applicable to power integrated circuits.PMOS performance can be improved by depositing a compressive stress film on the surface of the chip,but this will degrade the performance of the N-type LDMOS.The performance of the PMOS is improved by a compressive SiN film on the surface of the chip,but this will degrade the performance of the N-type LDMOS.Although it is possible to etch the CESL on the surface of LDMOS,the etching process is difficult,and it will damage the surface of the device,which will degrade the device performance.In addition,if tensile CESL is specially deposited on the surface of the NLDMOS device,since the stress properties of the conventional LDMOS drift region and the channel region are reversed.This leads to the mobility in the channel region is improved,and the drift region mobility is increased.It makes the role of the stress film very limited.In view of this,this paper proposes a novel LDMOS device combined with CESL strain technology and trench structure.The use of a trough structure reverses the nature of the stress in channel,so that the stress properties in the drift and the channel region are consistent.The compressive CESL improves the performance of the LDMOS,and the related process is compatible with the strained PMOS process,thereby facilitating the integration of NLDMOS and PMOS.According to the theory of solid mechanics,for a thin-strain elastic material with local projections or depressions,the stress of the raised or recessed area is very different from that of its peripheral area,and even stress reversal occurs.This paper is to use this effect,through the preparation of the appropriate slot-shaped structure on the surface of the strained silicon,to reverses the nature of the stress in channel,thereby improving the performance of the device.The simulations performed by TCAD validated our ideas and confirmed that the strained NLDMOS with trench-based structure have significantly improved performance over common devices.For the trench-based drift NLDMOS with a gate length of 180 nm and a drift region at 330 nm,the drive current is increased by 11.9%,the maximum transconductance is increased by 10.9%,and the cutoff frequency is increased by 10.6%.The simulation results will provide data support for the subsequent experimental work.