An (*) anisotropic form of this technique uses alkali hydroxides and reveals <111> planes, and doping with boron provides a "stop" layer for it.  
It has little to do with ammonia, but one form of this technique uses the Bosch process, and is a variant of a process that uses a radio frequency power source to create a plasma.  In addition to the "deep reactive ion" form, another form of this technique uses gaseous xenon difluoride and is known as the "vapor phase" form.  An (*) anisotropic form of this technique uses alkali hydroxides and reveals <111> planes, and doping with boron provides a "stop" layer for it.  Though it is commonly done with a silicon-based substrate, this process can be accomplished with any metal substrate by using aqua regia.  For 10 points, name this process typically used in integrated circuit and MEMS fabrication, in which material is removed from a wafer.
It has little to do with ammonia, but one form of this technique uses the Bosch process, and is a variant of a process that uses a radio frequency power source to create a plasma.  
{etch}ing [accept {dry etch}ing until “alkali”; accept {deep reactive ion etch}ing until mentioned] (5) [DW]