Semiconductor device and method of manufacturing same
AssigneeRenesas Electronics Corporation
InventorsKoji IIZUKA, Hidenori SATO
Life of this patent
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Abstract
To provide a solid state image sensor having improved sensitivity and at the same time, causing less dark current, noise, and the like. In a solid state image sensor having a substrate comprised of an N type semiconductor substrate and a P type epitaxial layer thereon, formed are a trench penetrating the epitaxial layer in an isolation region between a pixel region having therein array of pixels and a peripheral circuit region around the pixel region; and a DTI structure comprised of an insulating film with which the trench is filled. Transfer of electrons in the substrate between the pixel region and the peripheral circuit region is thereby prevented.
Claims15
A semiconductor device having a solid state image sensor equipped with a pixel including a photodiode, comprising:
- a semiconductor substrate having an N conductivity type;
- a semiconductor layer formed over the semiconductor substrate and having a P conductivity type;
- a plurality of the photodiodes formed in an upper surface of the semiconductor layer in a first region;
- a transistor formed over the semiconductor layer in a second region surrounding the first region in plan view;
- an element isolation region buried in a first trench formed in the upper surface of the semiconductor layer between the photodiodes;
- and
- an isolation portion including a first insulating film formed in the semiconductor layer in a third region between the first region and the second region and formed in a second trench deeper than the first trench.
A method of manufacturing a semiconductor device having a solid state image sensor equipped with a pixel including a photodiode, comprising the steps of:
- (a) providing a semiconductor substrate having an N conductivity type;
- (b) forming an epitaxial layer having a P conductivity type over the semiconductor substrate;
- (c) forming a plurality of photodiodes in an upper surface of the epitaxial layer in a first region;
- (d) forming a transistor over the upper surface of the epitaxial layer in a second region surrounding the first region in plan view;
- (e) forming an element isolation region that isolates the photodiodes from each other in a first trench formed in the upper surface of the epitaxial layer;
- (f) forming a second trench deeper than the first trench in the upper surface of the epitaxial layer in a third region between the first region and the second region;
- and
- (g) filling the second trench with a first insulating film and thereby forming an isolation portion including the first insulating film.
Dependencies are inferred from the claim text.