The Influence Of Layout Design To Circuit Design

In this paper, it mainly presents the significance meaning of layout design in the current highly integration semiconductor device design. The paper is based on the actual project of high speed ADC as a starting point. Because as the precision of conversion digits of ADC and the development trend of high Bit number, the requirement for ADC conversion rate and the speed of response is getting higher and higher. So the practical working speed of ADC is becoming faster and faster too. Thus the final performance of circuit is influenced by layout design is more and more.In this article, we first start with the possible problems in terms of layout design. Second analyze the quantitative model of the effect of these problems, such as STI effect, WPE effect, the matching of layout devices and the introduction of the parasitic capacitance, etc. Besides we also analyze the possible problems of the layout by these effects. And then, bring the quantitative model to the actual design development flow, in order to make a better control in the beginning of the layout design. And then, using the actual layout design as example, we can observes the difference of the data from the back-end simulation results, also we observe back-end simulation results of the WPE model and matching model respectively. So we can find the effectiveness of the design results by adding model.In the last of the article, we focus on the actual project and compare the front end simulation results (without layout effect) and the back-end simulation results (with layout effect). From the results of the comparison, we can get two points:first, layout design do to affect the design unavoidably; second the influence of layout design can be avoid in the good layout design. Then we can summarize that layout design plays an important role to the electric properties of overall design.