CIBSOC Program – Spiral Inductor Inductance Calculation and Layout Optimization Claudia Pacurar 1 , Vasile Topa 1 , Adina Racasan 1 , Calin Munteanu 1 1 Technical University of Cluj-Napoca, 26-28 Baritiu Street, Romania, Claudia.Pacurar@et.utcluj.ro ; Vasile.Topa@et.utcluj.ro ; Adina.Racasan@et.utcluj.ro ; Calin.Munteanu@et.utcluj.ro Summary Spiral inductors are very often used in integrated circuits for many applications. To design spiral inductors or to improve the spiral inductors performances is absolutely necessary to calculate theirs inductances and/or to optimize theirs layouts. In this effect we create a software program, named CIBSOC (Spiral Inductors Inductance Calculation and Layout Optimization). The program is dedicated to calculate dc inductances and to optimize layouts for spiral inductors. We use a wide range of inductors in the applications made with our program. We compare the results of our applications with the measurements results existing in the literature and also with the results that we have obtained using a commercial field solver in order to validate our program. Our program is accurate enough, has a very friendly interface, is very easy to use and it calculates the problems in a very sort running time compared with other similar programs. Since spiral inductors tolerance is generally on the order of several percent, a more accurate program is not needed in practice. The program is very useful for the spiral inductors design, because it calculates the inductance of spiral inductors with a very good accuracy. It is also useful for the spiral inductors optimization, because it affords optimal solutions for spiral inductor layouts in terms of the technological limitations and/or of the users’ needs. 1. Introduction The passive components parameters extraction from radio frequency integrated circuits such as inductance, capacitance and resistance extraction are research topics of great interest and also very provocative. This fact is motivate by the continual technological progress thanks to it is now possible to implement integrated circuit at microns dimensions. The minimization of the integrated circuit dimensions at this extreme level lead in an implicit way to the significant rise of parameters extraction importance. These parameters must be calculated with a very good accuracy. We focus on inductance calculation. The inductance value extraction was and is intense studied in the literature. At this moment exists many expressions and methods used for integrated circuits inductance extraction [1]-[5], but as is mentioned in the literature, there are limits in their application. 2. CIBSOC Software Program To design and to optimize the spiral inductors from integrated circuits is first necessary to find the exact parameters values, such as inductance value. So the fast and accurate inductance extractions become more and more important for design, optimization and design verification of the spiral inductors and for their performances improvement. The exact inductance calculation for spiral inductors; the spiral inductors optimization by finding their optimal layout for a given maximal inductance or for any given inductance value keeping a constant area for the inductor implementation in the integrated circuits are still needed to improve the spiral inductors performances. To this aim we implement a software program that allow fast and accurate inductance calculation and spiral inductor layout optimization. The program is composed of four modules. The first and the second one are create to calculate the spiral inductor inductance. The third and the fourth one are created to optimize the spiral inductor layout. 3. Applications in CIBSCO Program We create a set of spiral inductors and we implement them in our program to find theirs inductances and to optimize theirs layouts. We present in this paper only the spiral inductors with square shape, even if the program allows also the calculation for hexagonal, octagonal and circular shapes of spiral inductors. We use CIBSOC program to calculate the total inductance for each of the square spiral inductor that we create and to optimize theirs layouts. All the dimensions used in the paper are in [μm] and the inductance values in [nH].