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The low on-resistance and
the high BV in lateral RESURF devices make them desirable for use in
HVIC technologies. Although desirable, RESURF devices suffer
from the unique requirement of accurate charge control and they are very sensitive to
charge balance. Variations on charge control may lead to a lower BV
causing limitations on the device performance. This control requirement complicates
the manufacturability of RESURF devices affecting their overall behavior.
Unless careful process control and/or charge balance methodologies are implemented, it
is difficult to obtain a BV that is reproducible in fabrication.
This charge balance sensitivity and the associated BV modulation
are critical especially for double-RESURF devices.
Actually, in double-RESURF technology, the additional 
-top layer requires a tight
charge control and, therefore, adds more complexity to charge control requirements.
The mandatory accurate charge control requirements make the implementation of
RESURF devices with controllable BVs difficult.
At present, device designers tend to adjust and optimize the process variables to meet the device layout design requirements. This approach prevents and masks device designers from achieving the best performance of the process, further complicating the charge control requirements. Since the use of RESURF technology is highly dependent on the accuracy and control of key process parameters,a careful strategy in optimizing these parameters independent of layout optimization is an important requirement of such technology.
Ideally, in order to achieve the best from the RESURF technology and to gain insights into its manufacturability, it is important to decouple the process optimization from the device layout optimization. Consequently, before optimal device layout designs in a RESURF technology are possible, it is critical to determine the unique charge control requirements and to assess their manufacturing tolerances. In fact, for the correct application of high-performance RESURF technology, a measure of the manufacturing window of RESURF devices prior to actual device layout is important for optimizing and gauging the possible improvements in device layout.