IC Layout Basics: A Practical Guide
This book teaches the basics of IC (Integrated Circuit) layout in jargon-free, plain-English, understandable to those without an EE degree.
TABLE OF CONTENTS IC Layout Basics: A Practical Guide
Try It
Use the above ohm-micron equation to calculate the contact resistance for the following resistors.
| 1. | Given a contact resistance factor of 100 ?-microns, calculate the ohms through each of these resistors:
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| 2. | Given a contact resistance factor of 22 ?-microns, calculate the ohms through each of these resistors:
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Answers
| 1. | Divide ?-microns by width (given in microns). |
| 2. |
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Using the ohm-micron factor, R c, to determine our contact resistance makes our total resistance equation look like this:
| R total | = | total resistance (ohms) |
| L b | = | length of body (microns) |
| W b | = | width of body (microns) |
| ? b | = | sheet resistivity of the resistor body (ohms-per-square) |
| R c | = | resistance factor of the contact (ohm-microns) |
| W c | = | width of the contact (microns) |
| Note | The contact width may not necessarily be the same width as the resistor. Depending on the design rules of a process the contact may need to be smaller than the resistor. |
Copyright Christopher Saint and Judy Saint 2002 under license agreement with Books24x7
