| Sheet Resistance |
Article Index for Sheet |
Website Links For Sheet |
Information AboutSheet Resistance |
| CATEGORIES ABOUT SHEET RESISTANCE | |
| semiconductors | |
|
The sheet resistance is a measure of Semiconductor regions (e.g. Silicon or Polysilicon ), and the resistors which are screen printed onto the substrates of Thick Film Hybrid Microcircuits . The utility of sheet resistance, as opposed to Resistance or Resistivity , is that it is directly measured using a Four-terminal Sensing measurement (also known as a four-point probe measurement). Sheet resistance is measured in Ohm s/square , and is applicable to two-dimensional systems where the thin film is considered to be a two dimensional entity. It is equivalent to Resistivity as used in three-dimensional systems. When the term sheet resistance is used, the current must be flowing along the plane of the sheet, not perpendicular to it. In a regular three-dimensional conductor, the Resistance can be written as : where is the resistivity, is the cross-sectional area and is the length. The cross-sectional area can be split into the width and the sheet thickness . By grouping the resistivity with the thickness, the resistance can then be written as : is then the sheet resistance. Because it is multiplied by a dimensionless quantity, the units are ohms. The term ohms/square is used because it gives the resistance in ohms of current passing from one side of a square region to the opposite side, regardless of the size of the square. For a square, . Therefore, for any size square. REFERENCES General references |
|
|