Automated Design for Micromachining

Euler Columns

Introduction

This cell implements an array of Euler columns. The lengths of the Euler columns are varied to provide a pseudo-meter capable of measuring compressive stress.

Please also refer to the documentation for the euler column parameterized cell.

Theory

Please also refer to the documentation for the euler column parameterized cell.

Parameters

Any parameter may be modified, if necessary, to meet design rules. Typically, this involves increasing parameters that specify distances, so that minimum line width and minimum line spacing rules will not be violated. This has been extended to the convention of specifying a zero for some parameters to obtain an instance of the minimum size.

In addition to the parameters listed below, several technology parameters also influence the implementation of parameterized cells. This data must be present in the technology library.

Table 1: Parameters for the 'euler_columns' parameterized cell.
Name Description Range Units
layer This parameter is the drawing layer for the comb. These are POLY1, POLY2, or double-thickness structures. - -
length (min) The length of the shortest Euler column. [0,∞) um
length (max) The length of the longest Euler column. [0,∞) um
length step When creating the array, this parameter determines the difference in Euler column lengths. [0,∞) um
width The width of the beam. While this may play a role in the Euler Buckling load, the buckling stress is independent of the width. This parameter is automatically increased if it is less than the nominal width. [0,∞) um
anchor size The size of the anchors used to connect the cantilevers to the substrate. If this value is less then the nominal width it will be increased. [0,∞) um
include poly0 If true, a POLY0 ground plane will be included in the cell. The POLY0 ground plane can eliminate most electrostatic attraction between the Euler column and the substrate bulk. true/false -

References

[1] H. Guckel, T. Randazzo, and D.W. Burns. "A simple technique for the determination of mechanical strain in thin films with applications to polysilicon," Journal of Applied Physics. vol. 57, no. 5, pp. 1671-5 (1985).

[2] W. Fang and J.A. Wickert. "Post-buckling of micromachined beams," Journal of Micromechanics and Microengineering. vol. 4, no. 3, pp. 116-22 (1994).