Abstract: Aspects of the invention provide a method of forming a bipolar junction transistor. The method includes: providing a semiconductor substrate including a uniform silicon nitride layer over an emitter pedestal, and a base layer below the emitter pedestal; applying a photomask at a first end and a second end of a base region; and performing a silicon nitride etch with the photomask to simultaneously form silicon nitride spacers adjacent to the emitter pedestal and exposing the base region of the bipolar junction transistor. The silicon nitride etch may be an end-pointed etch.

Abstract: Aspects of the invention provide a method of forming a bipolar junction transistor. The method includes: providing a semiconductor substrate including a uniform silicon nitride layer over an emitter pedestal, and a base layer below the emitter pedestal; applying a photomask at a first end and a second end of a base region; and performing a silicon nitride etch with the photomask to simultaneously form silicon nitride spacers adjacent to the emitter pedestal and exposing the base region of the bipolar junction transistor. The silicon nitride etch may be an end-pointed etch.

Abstract: Aspects of the invention provide a method of forming a bipolar junction transistor. The method includes: providing a semiconductor substrate including a uniform silicon nitride layer over an emitter pedestal, and a base layer below the emitter pedestal; applying a photomask at a first end and a second end of a base region; and performing a silicon nitride etch with the photomask to simultaneously form silicon nitride spacers adjacent to the emitter pedestal and exposing the base region of the bipolar junction transistor. The silicon nitride etch may be an end-pointed etch.

Abstract: Aspects of the invention provide a method of forming a bipolar junction transistor. The method includes: providing a semiconductor substrate including a uniform silicon nitride layer over an emitter pedestal, and a base layer below the emitter pedestal; applying a photomask at a first end and a second end of a base region; and performing a silicon nitride etch with the photomask to simultaneously form silicon nitride spacers adjacent to the emitter pedestal and exposing the base region of the bipolar junction transistor. The silicon nitride etch may be an end-pointed etch.

Abstract: Embodiments of the invention provide methods of sealing a micro electromechanical systems (MEMS) cavity and devices resulting therefrom. A first aspect of the invention provides a method of sealing a micro electromechanical systems (MEMS) cavity in a substrate, the method comprising: forming in a substrate a cavity filled with a sacrificial material; forming a lid over the cavity; forming at least one vent hole over the lid extending to the cavity; removing the sacrificial material from the cavity; depositing a first material onto the lid such that a size of at least one vent hole at a surface of the substrate is reduced but not sealed; and depositing a second material onto the first material to seal the at least one vent hole, wherein a MEMS cavity within the substrate and beneath the at least one vent hole substantially retains a pressure at which the at least one vent hole is sealed by the second material.