Patent ID: 8652971

Claim:
A microelectronic mechanical system (MEMS) device, comprising: a substrate; an overlying layer disposed over said substrate; a device access hole through said overlying layer; a device cavity in said substrate under said device access hole, such that said device cavity underlaps said overlying layer so that a lateral edge of said device cavity extends at least 5 microns past a lateral edge of said device access hole; and a cavity etch monitor disposed proximate to said device cavity, said cavity etch monitor comprising: a monitor access hole through said overlying layer; a monitor cavity in said substrate under said monitor access hole, such that said monitor cavity underlaps said overlying layer so that a lateral edge of said monitor cavity extends at least 5 microns past a lateral edge of said monitor access hole; and a first monitor scale disposed over said lateral edge of said monitor cavity, said first monitor scale including scale indicia to indicate a location of said lateral edge.