Electronic device, method for manufacturing the same, and silicon substrate for electronic device

Abstract

An electronic device is formed by epitaxially growing a Si substrate on a Si layer of an SOI substrate in which the Si layer is deposited on a front surface of a substrate with an insulating layer interposed therebetween; forming an element on a front-surface side of the Si substrate; and forming a back-surface element aligned with respect to the element, on a back-surface side of the Si substrate after the substrate is etched. A mark is formed by etching and removing the Si layer and the insulating layer in a predetermined position of the SOI substrate. The element is formed using a concave part as a reference position. The concave part appears on the front surface of the Si substrate epitaxially grown on the mark. The back-surface element is formed using the mark as a reference position. The mark appears after the substrate is etched.

1 . An electronic device comprising:
 a silicon substrate for the electronic device that is epitaxially grown on a silicon layer of an SOI substrate in which the silicon layer is deposited on a front surface of a semiconductor substrate with an insulating layer interposed therebetween;   a front-surface element formed on a front-surface side of the silicon substrate for the electronic device; and   a back-surface element formed on a back-surface side of the silicon substrate for the electronic device after the semiconductor substrate of the SOI substrate is etched, with being aligned with respect to the front-surface element, wherein:   a back-surface mark is formed by etching and removing the silicon layer and the insulating layer in a predetermined position of the SOI substrate,   the front-surface element is formed using a concave part as a reference position, the concave part appearing, on the front surface of the silicon substrate for the electronic device epitaxially grown on the back-surface mark, and   the back-surface element is formed using the back-surface mark as a reference position, the back-surface mark appearing after the semiconductor substrate is etched.   
     
     
         2 . The electronic device according to  claim 1 , wherein
 the electronic device is a back-illuminated solid-state imaging element,   the front-surface element comprises a photoelectric conversion element and a signal reading-out unit, and   the back-surface element comprises an optical element opposed to the photoelectric conversion element.   
     
     
         3 . The electronic device according to  claim 2 , wherein the signal reading-out unit comprises a charge transfer unit. 
     
     
         4 . A silicon substrate for electronic device manufactured by
 epitaxially growing a silicon substrate on a silicon layer of an SOI substrate in which the silicon layer is deposited on a front surface of a semiconductor substrate with an insulating layer interposed therebetween;   forming a front-surface element on a front-surface side of the silicon substrate; and   forming a back-surface element, that is aligned with respect to the front-surface element, on a back-surface side of the silicon substrate after etching the semiconductor substrate of the SOI substrate, wherein   a back-surface mark is formed by etching and removing the silicon layer and the insulating layer in a predetermined position of the SOI substrate,   the front-surface element is formed using a concave part as a reference position, the concave part appearing, on the front surface of the silicon substrate for the electronic device formed on the back-surface mark, and   the back-surface element is formed using the back-surface mark as a reference, the back-surface mark appearing after the semiconductor substrate is etched.