Analysis of current flow in mono-crystalline electrical linewidth structures

The current flow in lightly doped mono-crystalline silicon structures designed for use as low cost secondary reference linewidth standards is investigated. It is demonstrated that surface charge can have a significant effect upon the measurements of linewidth test structures. The effect of surface charge on <110> Greek cross structures is also investigated and the influence of a gate electrode on the extracted value of sheet resistance demonstrated. It is confirmed that the resulting uncertainty in both of these measurements can be simply overcome by degenerately doping the silicon during the fabrication process.