Solid-state imaging device and method for manufacturing thereof

Abstract

A solid-state imaging device is formed by laminating a photodiode on a surface of a Si semiconductor substrate, a gate electrode layer to read out or transfer electric charge stored on the photodiode, a first inter-layer insulating film made of SiO2, a first metallic wiring layer, a second inter-layer insulating film made of SiO2, a second metallic insulating layer, an undoped silicon glass (USG) film containing hydrogen, and a passivation film containing hydrogen, one by one. Dark currents are reduced by exhausting hydrogen atoms in the USG film and the passivation film for bonding it with dangling bonds on the surface of the Si semiconductor substrate, while applying heat treatments to the imaging device at a temperature of 400 DEG C. or higher.

Description

[0001] Cross References to Related Applications [0002] This application is based on and claims priority from Japanese Patent Application No. 2006-067216 filed on March 13, 2006, the contents of which are hereby incorporated by reference. technical field [0003] The present invention relates to a solid-state imaging device and a manufacturing method thereof, in particular to a solid-state imaging device capable of reducing dark current and a manufacturing method thereof. Background technique [0004] In a solid-state imaging device using a CCD or a CMOS sensor, a semiconductor such as amorphous silicon that has no periodicity in atomic arrangement and has a large number of dangling bonds that do not participate in atomic bonding at the interface of the SiO2 / Si structure is used Device structure. In the presence of such dangling bonds, in the manufacturing process of the solid-state imaging device, what is called a dark current occurs due to the presence of interface energ...

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Problems solved by technology

[0006] Recently, with the advancement of miniaturization of the cells constituting the solid-state imaging device, microfabrication of metal wiring is also required, and barrier metal (Barrier Metal) wiring structures such as Ti / TiN are widely used. In a solid-state imaging device with a wiring structure, if hydrogen is released by heat treatment in the final process of manufacturing the solid-state imaging device, blockage of hydrogen atoms will occur due to barrier metal wiring, and it will not be possible to provide sufficient support for the dangling bonds in the silicon substrate. hydrogen atoms, there is a problem that the dark current cannot be sufficiently reduced (refer to Japanese Laid-Open Patent Publication No. 8-45926)

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