Benefits of the lateral resistor in a FED

A protective resistor in series with a microtip is known to homogenize field emission. It is not widely recognized, however, that this protective resistor must be fail-safe as well, since the microtips are exposed to rare but potentially destructive events during life. This paper addresses two proposed protective resistor concepts: (a) a vertical resistor located locally underneath each microtip, and (b) a lateral resistor radially distributed from the center of each microtip. It is shown by electrical and thermal analysis that the lateral resistor is significantly more fail-safe than the vertical resistor by factors of about 10/spl times/ and 100/spl times/, respectively.