Semiconductor device with sealed cap

• US 8,349,634 B2
• Filed: 06/29/2010
• Issued: 01/08/2013
• Est. Priority Date: 02/22/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujii, Tetsuo, Sugiura, Kazuhiko
• Primary Examiner(s): ARORA, AJAY
• Application Number:
  US12/801,845
• Publication Number:
  US 20100270630A1
• Time in Patent Office: 924 Days
• Field of Search: 257/414, 438/48
• US Class Current: 438/48
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A semiconductor device includes: a first substrate made of semiconductor and having first regions, which are insulated from each other and disposed in the first substrate; and a second substrate having electric conductivity and having second regions and insulation trenches. Each insulation trench penetrates the second substrate so that the second regions are insulated from each other. The first substrate provides a base substrate, and the second substrate provides a cap substrate. The second substrate is bonded to the first substrate so that a sealed space is provided between a predetermined surface region of the first substrate and the second substrate. The second regions include an extraction conductive region, which is coupled with a corresponding first region.

Claims

1. A manufacturing method, comprising:

preparing the base substrate;

preparing the cap substrate;

bonding the cap substrate on the base substrate through the conductive film so that the sealed space is formed; and

electrically coupling the extraction conductive region with a corresponding base semiconductor region through the conductive film,

wherein the semiconductor device includes

a base substrate made of a SOI substrate having a SOI layer, an embedded oxide film and a silicon substrate, which are stacked in this order;

a plurality of first trenches disposed on the SOI layer and reaching the embedded oxide film;

a plurality of base semiconductor regions disposed in the SOI layer and insulated from each other with the plurality of first trenches, wherein at least one of the plurality of base semiconductor regions is a movable semiconductor region having a movable electrode, and wherein at least another one of the plurality of base semiconductor regions is a fixed semiconductor region having a fixed electrode, which faces the movable electrode;

a physical quantity sensor provided by the movable electrode and the fixed electrode for detecting a physical quantity based on a capacitance between the movable electrode and the fixed electrode, wherein the movable electrode is movable according to the physical quantity applied to the sensor so that a distance between the movable electrode and the fixed electrode is changeable;

a cap substrate made of single crystal silicon and having electric conductivity;

a plurality of second trenches, which penetrate the cap substrate;

a plurality of cap conductive regions made of single crystal silicon and insulated from each other with the plurality of second trenches; and

a conductive film disposed between the base substrate and the cap substrate so that the base substrate and the cap substrate are bonded to each other,

wherein a sealed space is provided between the base substrate and the cap substrate,

wherein the physical quantity sensor is sealed in the sealed space,

wherein a predetermined number of the cap conductive regions are electrically coupled with corresponding base semiconductor regions through the conductive film so that the predetermined number of the cap conductive regions provide a predetermined number of extraction conductive regions,

wherein the movable semiconductor region is coupled with one extraction conductive region, and the fixed semiconductor region is coupled with another extraction conductive region, and

wherein each extraction conductive region is exposed on a side of the cap substrate, which is opposite to the base substrate,

wherein the preparing the cap substrate includes;

forming a concavity on one side of a primary substrate, which faces the base substrate;

forming a plurality of primary insulation trenches on the one side of the primary substrate, wherein each primary insulation trench has a predetermined depth; and

grinding the other side of the primary substrate, which is opposite to the one side so that one end of each of the primary insulation trenches is exposed on the other side,

wherein each of the primary insulation trenches provides a corresponding second trench, and the primary substrate provides the cap substrate, and

wherein a periphery of the cap substrate around the concavity is bonded to the base substrate.

2. A manufacturing method, comprising:

preparing the base substrate;

preparing the cap substrate;

bonding the cap substrate on the base substrate through the conductive film so that the sealed space is formed; and

electrically coupling the extraction conductive region with a corresponding base semiconductor region through the conductive film,

wherein the semiconductor device includes

a base substrate made of a SOI substrate having a SOI layer, an embedded oxide film and a silicon substrate, which are stacked in this order;

a plurality of first trenches disposed on the SOI layer and reaching the embedded oxide film;

a plurality of base semiconductor regions disposed in the SOI layer and insulated from each other with the plurality of first trenches, wherein at least one of the plurality of base semiconductor regions is a movable semiconductor region having a movable electrode, and wherein at least another one of the plurality of base semiconductor regions is a fixed semiconductor region having a fixed electrode, which faces the movable electrode;

a physical quantity sensor provided by the movable electrode and the fixed electrode for detecting a physical quantity based on a capacitance between the movable electrode and the fixed electrode, wherein the movable electrode is movable according to the physical quantity applied to the sensor so that a distance between the movable electrode and the fixed electrode is changeable;

a cap substrate made of single crystal silicon and having electric conductivity;

a plurality of second trenches, which penetrate the cap substrate;

a plurality of cap conductive regions made of single crystal silicon and insulated from each other with the plurality of second trenches; and

a conductive film disposed between the base substrate and the cap substrate so that the base substrate and the cap substrate are bonded to each other,

wherein a sealed space is provided between the base substrate and the cap substrate,

wherein the physical quantity sensor is sealed in the sealed space,

wherein a predetermined number of the cap conductive regions are electrically coupled with corresponding base semiconductor regions through the conductive film so that the predetermined number of the cap conductive regions provide a predetermined number of extraction conductive regions,

wherein the movable semiconductor region is coupled with one extraction conductive region, and the fixed semiconductor region is coupled with another extraction conductive region, and

wherein each extraction conductive region is exposed on a side of the cap substrate, which is opposite to the base substrate,

wherein the preparing the cap substrate includes;

forming a plurality of primary insulation trenches on one side of a primary substrate, wherein each primary insulation trench has a predetermined depth;

grinding the other side of the primary substrate, which is opposite to the one side, so that one end of the primary insulation trench is exposed on the other side; and

forming a concavity on the other side of the primary substrate, which faces the base substrate, after the grinding,

wherein each of the primary insulation trenches provides a corresponding second trench, and the primary substrate provides the cap substrate, and

wherein a periphery of the cap substrate around the concavity is bonded to the base substrate.