Solid-state imaging device, production method thereof, and electronic device

Abstract

Disclosed is a solid-state imaging device which includes a pixel section, a peripheral circuit section, a first isolation region formed with a STI structure on a semiconductor substrate in the peripheral circuit section, and a second isolation region formed with the STI structure on the semiconductor substrate in the pixel section. The portion of the second isolation region buried into the semiconductor substrate is shallower than the portion buried into the semiconductor substrate of the first isolation region, and the height of the upper face of the second isolation region is equal to that of the first isolation region. A method of producing the solid-state imaging device and an electronic device provided with the solid-state imaging devices are also disclosed.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention generally relates to solid-state imaging devices, production methods thereof, and electronic devices provided with the solid-state imaging devices.[0003]2. Description of the Related Art[0004]Solid-state imaging devices are broadly classified into amplification type solid-state imaging devices, which are typically illustrated by CMOS (complementary metal-oxide semiconductor) image sensors, and charge transfer type imaging devices, which are typified by CCD (charge-coupled device) image sensors. The solid-state imaging devices have been used extensively in digital still cameras, digital camcorders, etc. In addition, as solid-state imaging devices mounted in mobile devices such as cellular phones with camera, PDA (personal digital assistant), etc., CMOS image sensors are used more frequently in recent years owing to relatively low source voltages and low power consumption characteristics among others.[0005]I...

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Benefits of technology

[0021]In the electronic device according to the embodiment of the present invention, in the solid-state imaging device, the portion buried into the semiconductor substrate of the second isolation region in the pixel section is shallower than the portion buried into the semiconductor substrate of the first isolation region in the peripheral circuit section, so that adverse effects of stresses and damages by the second isolation region onto the photoelectric conversion element are suppressed. The surface height of the second isolation region in the pixel section is made to be equal to and as low as that of the first isolation region in the peripheral circuit section, so that in fabricating gate electrodes after forming device separation regions, no electrode material remains on the sidewalls of the device separation regions. Because the surface height of the second isolation region in the pixel section is made equal to that of the first isolation region in the peripheral circuit section, the increase of the processing steps due to the difference in the STI structures of the first and second isolation regions can be suppressed to a minimum.

[0022]With the electronic device according to the embodiment of th

Problems solved by technology

With regard to isolation regions in the solid-state imaging device, the former of the abovementioned structures, which forms the regions with the same STI structure in both the pixel section and the peripheral circuit section, is known to have a problem of increasing white spots.

Namely, since the STI isolation regions in the pixel section are formed deep into the semiconductor substrate similarly to the STI isolation regions in the peripheral circuit section, the effects of stresses and damages exerted onto the photodiode increase, and this results in the increase of white spots.

However, in this case, there is a problem of increasing the number of processes, since the formation of the abovementioned diffusion region has to

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