High Frequency Deep-Submicron CMOS device and circuit modeling

• Main Authors: Chen, kuan-hao, 陳冠豪
• Other Authors: Lin, jeng-ping
• Format: Others
• Language: en_US
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/02579999569987998973

碩士 === 長庚大學 === 電機工程研究所 === 88 === As the gate lengths of silicon MOSFET’s become smaller and smaller, The conventional device model is not accurate in the GHz range. Because BSIM3v3 has been widely accepted as a standard CMOS model for low and medium frequency applications, we must find a method to solve this problem. Recent research has proposed a high frequency device model by adding a complicated substrate resistance network and modifying the BSIM3v3 source code. So we study the sensitivities of S-parameter to each model parameter at 1GHz and some guide lines are given for parameter extraction. A parameter extraction technique utilizing S-parameter data at the GHz range is finally proposed for a SPICE BSIM3V3 for RF MOSFET. Besides, chip size increases and signal wavelengths approach interconnect wire lengths. Therefore, signal delay due to interconnect become a major concern for high-performance integrated circuits. That is because the capacitance and resistance of wires increase rapidly as chip size grows and the minimum feature size is reduced. The purpose of this project is to establish RF CMOS ring oscillators delay model and to study the sensitivity of delay time to device parameters. The dimensions of the multi-finger type MOSFET is W/L=200μm /0.25μm~W/L=200μm/0.5μm, but we use single finger type NMOS (W/L=5μm/0.35μm) and PMOS (W/L=10μm/0.35μm)devices in ring oscillator. The extracted substrate resistance in high frequency device model for multi-finger type devices cannot be directly applied to the single finger type device in ring oscillators. First, we will establish NMOS (W/L=5μm/0.35μm) model and PMOS (W/L=10μm/0.35μm) BSIM3V3 model. Second, the substrate resistances are extracted by measuring S-parameter of the multi-finger type MOSFET. The substrate resistances for the single finger type device are subsequently calculated according to a proposed method as described in Chapter4.In general, RF modification of BSIM3V3 model significantly improves the accuracy of the high-frequency performance prediction. Furthermore, For high frequency operation, According to the simulation of ring oscillator performance based on RF MOS model, with further consideration of delay time model’s interconnection effect, the accuracy of delay time prediction is much better improved.