Mems cavity with non-contaminating seal

A method of fabricating a semiconductor device, the method comprising:

• forming a microelectromechanical systems (MEMS) structure including a body, an electrode to perform at least one of exciting or sensing motion of the body, and an oxide adjacent the body;
• forming a lid layer over MEMS structure;
• wherein the method further includes forming at least one oxide-release vent through the lid layer, and etching the oxide through the at least one oxide-release vent so as to thereby free at least part of the body to move;
• forming a conductive path through the lid layer to the electrode;
• and
• sealing the at least one oxide-release vent;
• wherein the forming of the conductive path and the sealing of the at least one oxide-release vent each comprise a common fabrication step in which a material is used to plug the at least one oxide-release vent and in which the material is also used to form at least part of the conductive path to the electrode.

A method of fabricating a semiconductor device, the method comprising:

• patterning a silicon layer of a silicon on-oxide wafer to form a region;
• doping the region with an n-type dopant, such that the region has a dopant concentration of at least 1E19 atoms per cubic centimeter;
• forming a first layer of oxide above the doped region;
• forming a body above the oxide, the body having at least one layer of a piezoelectric substance;
• forming a second layer of oxide above the body;
• forming a lid layer over the second layer of oxide;
• forming at least one oxide-release vent through the lid layer;
• etching part of the first layer of oxide and part of the second layer of oxide in a vicinity adjacent at least part of the body, through the at least one oxide-release vent, so as to thereby release the at least part of the body such that it is free to move;
• forming a trench extending through the lid layer to the doped region;
• and
• filling at least part of the trench with a material and sealing the at least one oxide-release vent with the material in a common fabrication step;
• wherein the method further comprises forming a microelectromechanical systems (MEMS) structure, the MEMS structure including the body and an electrode to perform at least one of exciting or sensing motion of the body, wherein the electrode comprises the doped region;
• wherein the material in the trench is to form at least part of a conductive path extending from an external surface of the lid layer to the electrode.

A method of fabricating a semiconductor device, the method comprising:

• forming a microelectromechanical systems (MEMS) structure including a body, an electrode to perform at least one of exciting or sensing motion of the body, and an oxide adjacent the body;
• forming a lid layer over MEMS structure;
• wherein the MEMS structure is a MEMS resonator and the body has a first end free to vibrate and a second end to tether the body to the semiconductor device;
• wherein the method further includes forming at least one oxide-release vent through the lid layer, and etching the oxide from an area adjacent the first end, through the at least one oxide-release vent, so as to thereby free the first end of the body to move;
• forming a conductive path through the lid layer to the electrode;
• and
• sealing the at least one oxide-release vent;
• wherein the forming of the conductive path and the sealing of the at least one oxide-release vent each comprise a common fabrication step in which a material is used to plug the at least one oxide-release vent and in which the material is also used to form at least part of the conductive path to the electrode.