Method and system for fabricating a MEMS device

A method comprising:

• depositing a first polysilicon layer over a first side of an actuator layer;
• forming a first intermetal dielectric (IMD) layer over the first polysilicon layer;
• etching the first IMD layer to form a via that exposes the first polysilicon layer and further to form a bump region;
• depositing a second polysilicon layer over the first IMD layer, the via and the bump region;
• etching a portion of the second polysilicon layer to expose a portion of the first IMD layer and to form a patterned second polysilicon layer;
• depositing a second IMD layer over the patterned second polysilicon layer and further over the exposed portion of the first IMD layer;
• etching a portion of the second IMD layer to expose a portion of the patterned second polysilicon layer and to form a patterned second IMD layer;
• depositing a third polysilicon layer over the patterned second IMD layer and further over the exposed portion of the second polysilicon layer;
• etching the third polysilicon layer to form a patterned third polysilicon layer;
• depositing a third IMD layer over the patterned third polysilicon layer and further over an exposed portion of the second IMD layer;
• fusion bonding the third IMD layer to a substrate;
• depositing a bond layer over a second side of an actuator layer, wherein the second side is opposite to the first side;
• patterning the bond layer to form a patterned bond layer;
• etching a pattern through the actuator layer, the first polysilicon layer and partially through the first IMD layer;
• and
• etching through the first IMD layer to form a cavity and further to expose a portion of the second polysilicon layer.