1.  Field of the Invention
The present invention relates to a semiconductor device, such as a solid-state imaging device, and a method of manufacturing such a semiconductor device.  The present invention also relates to an electronic apparatus, such as a camera, equipped with the semiconductor device. 
2.  Description of the Related Art
Solid-state imaging devices, which have been commonly used, include amplification-type solid-state imaging devices as typified by MOS image sensors such as complementary metal oxide semiconductors (CMOSs) and charge-transfer solid-state imaging devices as typified by charge coupled device (CCD) image sensors.  These solid-state imaging devices have been widely used for digital still cameras, digital video cameras, and so on.  Furthermore, in recent years, MOS image sensors have been used for most of solid-state imaging devices mounted on mobile devices such as camera cell-phones and PDAs (Personal Digital Assistants) because of their low power voltages, low consumption powers, and so on. 
The MOS solid-state imaging device includes a pixel array (pixel region) where a plurality of unit pixels are arranged in a two-dimensional array, and a peripheral circuit region.  The unit pixel is formed of a photodiode and a plurality of pixel transistors, serving as a photoelectric conversion part.  The pixel transistors may be three MOS transistors: a transfer transistor, a reset transistor, and an amplification transistor, or may be four in which a selection transistor is further included. 
Some of the MOS solid-state imaging devices are those in which a semiconductor chip with a pixel region on which a plurality of pixel is arranged is electrically connected to a semiconductor chip in which a logic circuit for signal processing is formed to form a single device.  Various kinds of such a device have been proposed.  For example, Japanese Unexamined Patent Application Publication No.  2006-49361 discloses a semiconductor module where a back-illuminated image sensor chip having a micro-pad for each pixel cell and a signal processing chip, on which a signal processing circuit is formed, having a micro-pad are connected to each other via a micro-bump.  Japanese Unexamined Patent Application Publication No.  2007-13089 discloses a device on which a sensor chip and a signal processing chip are mounted on an interposer (intermediate substrate).  The sensor chip is a back-illuminated MOS solid-state imaging device with an imaging pixel section and the signal processing chip is provided with a peripheral circuit performing signal processing.  In Japanese Unexamined Patent Application Publication No.  2008-130603, an imaging device includes an image sensor chip, a thin-layer circuit board, and a logic circuit chip for signal processing.  In addition, it also discloses the configuration of the device in which the thin-layer circuit board and the logic circuit chip are electrically connected to each other.  In this case, the thin-layer circuit board is electrically connected from the backside of the image sensor chip through a through-hole-via. 
In addition, Japanese Patent No.  4000507 discloses a solid-state imaging device provided with a penetration electrode on a solid-state imaging element supported on a transparent substrate, where the solid-state imaging element is electrically connected to a flexible circuit substrate.  Furthermore, Japanese Unexamined Patent Application Publication No.  2003-31785 discloses a back-illuminated solid-state imaging device provided with an electrode passing through a supporting substrate. 
As described in Japanese Unexamined Patent Application Publication Nos.  2006-49361, 2007-13089, and 2008-130603, various technologies for combining an image sensor chip with different circuit chips such as logic circuit have been proposed.  In these technologies, any of functional chips is almost completely built up in advance and then mounted on a substrate while being allowed to make a connection between the chips by the formation of a connection through hole.