Transistors with source-connected field plates

A method of fabricating a semiconductor device comprising:

• receiving a semiconductor substrate that includes a channel region suitable for use as a transistor channel;
• depositing a field plate dielectric layer in direct contact with a top surface of the substrate over the channel region, wherein the field plate dielectric layer has a first thickness;
• depositing a second dielectric layer over the channel region, wherein the second dielectric layer has a second thickness that is greater than the first thickness;
• simultaneously forming first and second apertures in the second dielectric layer above the channel region, wherein
• the first aperture is disposed at a location between a first end of the channel region and a second end of the channel region;
• and
• the second aperture is separated from the first aperture by a portion of the second dielectric layer and disposed at a location between the first aperture and the second end of the channel region;
• forming a control electrode within the first aperture, wherein the control electrode has a first end that directly contacts the top surface of the substrate, and a second end that overlies and contacts an upper surface of the second dielectric layer between the first aperture and the second aperture;
• depositing a third dielectric layer over the control electrode and within the second aperture;
• forming a third aperture in the third dielectric layer, wherein the third aperture spans and is wider than the second aperture;
• and
• forming a field plate electrode from an electrically conductive material that is simultaneously deposited in the second aperture and the third aperture, wherein a first end of the field plate electrode is separated from the top surface of the substrate by the field plate dielectric layer, and the electrically conductive material extends from the first end of the field plate electrode and from the second and third apertures over the control electrode.