Isolated junction field-effect transistor
AssigneesAdvanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
InventorsRichard K. Williams, Donald Ray Disney, Wai Tien Chan
Life of this patent
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Abstract
An isolation structure for a semiconductor device comprises a floor isolation region, a dielectric filled trench above the floor isolation region and a sidewall isolation region extending downward from the bottom of the trench to the floor isolation region. This structure provides a relatively deep isolated pocket in a semiconductor substrate while limiting the depth of the trench that must be etched in the substrate. An isolated junction field-effect transistor is formed in the isolated pocket.
Claims12
An isolated junction field-effect transistor comprising:
- a semiconductor substrate of a first conductivity type;
- a floor isolation region of a second conductivity type opposite to the first conductivity type submerged in the substrate;
- a filled trench comprising a dielectric material and extending downward from a surface of the substrate, a bottom of the filled trench being located above a top of the floor isolation region;
- a sidewall isolation region of the second conductivity type extending downward from a bottom of the filled trench at least to the top of the floor isolation region, the sidewall isolation region being submerged in the substrate and not extending upward to the surface of the substrate, the floor isolation region, filled trench and sidewall region together enclosing an isolated pocket of the substrate;
- a source region of the first conductivity type adjacent the surface of the substrate in the isolated pocket;
- a drain region of the first conductivity type adjacent the surface of the substrate in the isolated pocket;
- and
- a gate region of the second conductivity type disposed between the source and drain regions, a channel region of the transistor comprising an area of the isolated pocket between the gate region and the floor isolation region.
Dependencies are inferred from the claim text.