Semiconductor device and method of making the same

Abstract

A semiconductor device includes a sensor portion, a cap portion, and an ion-implanted layer. The sensor portion has a sensor structure at a surface portion of a surface. The cap portion has first and second surfaces opposite to each other and includes a through electrode. The surface of the sensor portion is joined to the first surface of the cap portion such that the sensor structure is sealed between the sensor portion and the cap portion. The ion-implanted layer is located on the second surface of the cap portion. The through electrode extends from the first surface to the second surface and is exposed through the ion-implanted layer.

1 . A method of making a semiconductor device comprising:
 preparing a sensor wafer having one side and including a plurality of sensor portions, each sensor portion having one surface on the side of the sensor wafer and including a sensor structure at a surface portion of the surface;   preparing a cap wafer having a front side and a back side opposite to the front side, the cap wafer including a plurality of cap portions, each cap portion having a first surface on the front side of the cap wafer and a second surface on the back side of the cap wafer;   forming a trench on the first surface of the cap portion;   forming an insulation layer on a wall of the trench;   forming a buried electrode on the insulation layer;   joining the side of the sensor wafer to the front side of the cap wafer such that the buried electrode of the cap portion is electrically connected to a contact region of the sensor structure of the sensor portion and such that the sensor structure is sealed between the sensor portion and the cap portion;   forming a through hole and a through electrode extending from the first surface to the second surface of the cap portion by removing the back side of the cap wafer until the trench and the buried electrode are exposed to a new surface of the back side of the cap wafer; and   dividing a joined body of the sensor wafer and the cap wafer into a plurality of semiconductor devices in the form of chips after the forming of the through electrode.   
   
   
       2 . The method according to  claim 1 , wherein
 the forming of the through electrode including:
 forming an ion-implanted layer in the cap wafer by implanting a plurality of ions into the back side of the cap wafer, the ion-implanted layer being located at a depth equal to or greater than a bottom of the trench measured from the back side of the cap wafer; 
 thermally treating the joined body of the sensor wafer and the cap wafer after the forming of the ion-implanted layer; and 
 separating the back side of the cap wafer with respect to the ion-implanted layer as a cleavage surface; so that the buried electrode is exposed to the new surface of the back side of the cap wafer. 
   
   
   
       3 . The method according to  claim 1 , wherein
 the forming of the through electrode includes mechanically polishing the back side of the cap wafer until the buried electrode is exposed to the new surface of the back side of the cap wafer.   
   
   
       4 . The method according to  claim 1 , wherein
 the forming of the through electrode includes polishing the back side of the cap wafer by chemical mechanical polishing until the buried electrode is exposed to the new surface of the back side of the cap wafer.   
   
   
       5 . The method according to  claim 1 , wherein
 the forming of the through electrode includes etching the back side of the cap wafer until the buried electrode is exposed to the new surface of the back side of the cap wafer.   
   
   
       6 . A method of making a semiconductor device comprising:
 preparing a sensor wafer having one side and including a plurality of sensor portions, each sensor portion having one surface on the side of the sensor wafer and including a sensor structure at a surface portion of the surface and a connection portion electrically connected to the sensor structure, the connection portion being located within a connection region on an outer region of the surface, the connection region of a first one of the plurality sensor portions facing the connection region of a second one of the plurality of sensor portions to form a cavity region between the sensor structure of the first one of the plurality sensor portions and the sensor structure of the second one of the plurality sensor portions;   preparing a cap wafer having a front side and a back side opposite to the front side, the cap wafer including a plurality of cap portions, each cap portion having a first surface on the front side of the cap wafer and a second surface on the back side of the cap wafer;   forming a recessed portion on the front side of the cap wafer;   joining the side of the sensor wafer to the front side of the cap wafer such that the cavity region of the sensor wafer is covered with a bottom of the recessed portion of the cap wafer and such that the sensor structure is sealed between the sensor portion and the cap portion;   forming an ion-implanted layer in the cap wafer by implanting a plurality of ions into the back side of the cap wafer, the ion-implanted layer being located at a depth equal to or greater than the bottom of the recessed portion measured from the back side of the cap wafer;   thermally treating a joined body of the sensor wafer and the cap wafer after the forming of the ion-implanted layer;   separating the back side of the cap wafer with respect to the ion-implanted layer as a cleavage surface to remove the bottom of the recessed portion after the thermally treating of the joined body, so that the cavity region is exposed to a new surface of the back side of the cap wafer through the recessed portion; and   dividing the joined body of the sensor wafer and the cap wafer into a plurality of semiconductor devices in the form of chips after the separating of the back side, so that the connection region of the sensor portion is exposed through the cap portion.   
   
   
       7 . A method of making a semiconductor device comprising:
 preparing a sensor wafer having one side and including a plurality of sensor portions, each sensor portion having one surface on the side of the sensor wafer and including a sensor structure at a surface portion of the surface and a connection portion electrically connected to the sensor structure, the connection portion being located within a connection region on an outer region of the surface, the connection region of a first one of the plurality of sensor portions facing the connection region of a second one of the plurality of sensor portions to form a cavity region between the sensor structure of the first one of the plurality sensor portions and the sensor structure of the second one of the plurality sensor portions;   preparing a cap wafer having a front side and a back side opposite to the front side, the cap wafer including a plurality of cap portions, each cap portion having a first surface on the front side of the cap wafer and a second surface on the back side of the cap wafer;   forming a recessed portion on the front side of the cap wafer   joining the side of the sensor wafer to the front side of the cap wafer such that the cavity region of the sensor wafer is covered with a bottom of the recessed portion of the cap wafer and such that the sensor structure is sealed between the sensor portion and the cap portion;   etching the back side of the cap wafer to remove the bottom of the recessed portion of the cap wafer, so that the cavity region is exposed to a new surface of the back side of the cap wafer through the recessed portion; and   dividing a joined body of the sensor wafer and the cap wafer' into a plurality of semiconductor devices in the form of chips after the separating of the back side, so that the connection region of the sensor portion is exposed through the cap portion.   
   
   
       8 . A method of making a semiconductor device comprising:
 preparing a sensor wafer having one side and including a plurality of sensor portions, each sensor portion having one surface on the side of the sensor wafer and including a sensor structure at a surface portion of the surface and a connection portion electrically connected to the sensor structure, the connection portion being located within a connection region on an outer region of the surface, the connection region of a first one of the plurality of sensor portions facing the connection region of a second one of the plurality of sensor portions to form a cavity region between the sensor structure of the first one of the plurality sensor portions and the sensor structure of the second one of the plurality sensor portions;   preparing a cap wafer having a front side and a back side opposite to the front side, the cap wafer including a plurality of cap portions, each cap portion having a first surface on the front side of the cap wafer and a second surface on the back side of the cap wafer;   forming a recessed portion on the front side of the cap wafer;   joining the side of the sensor wafer to the front side of the cap wafer such that the cavity region of the sensor wafer is covered with a bottom of the recessed portion of the cap wafer and such that the sensor structure is sealed between the sensor portion and the cap portion;   placing a dicing tape on the back side of the cap wafer after the joining of the sensor wafer to the cap wafer;   cutting a portion of the back side of the cap wafer through the dicing tape, the portion corresponding to the bottom of the recessed portion;   removing the dicing tape from the back side of the cap wafer to remove the cut portion from the cap wafer, so that the cavity region is exposed to the back side of the cap wafer through the recessed portion; and   dividing a joined body of the sensor wafer and the cap wafer into a plurality of semiconductor devices in the form of chips after the removing of the dicing tape, so that the connection region of the sensor portion is exposed through the cap portion.   
   
   
       9 . A semiconductor device comprising:
 a sensor portion having one surface and including a sensor structure at a surface portion of the surface and a connection portion electrically connected to the sensor structure;   a cap portion having a first surface and a second surface opposite to the first surface, the cap portion including a through hole extending from the first surface to the second surface, an insulation layer formed on a wall of the through hole, and a through electrode formed on the insulation layer, the through electrode extending from the first surface to the second surface through the through hole and electrically connected to the connection portion of the sensor portion; and   an ion-implanted layer disposed on the second surface of the cap portion, wherein   the surface of the sensor portion is joined to the first surface of the cap portion such that the sensor structure is sealed between the sensor portion and the cap portion, and   the through electrode is exposed through the ion-implanted layer.   
   
   
       10 . The semiconductor device according to  claim 9 , wherein
 a surface of the ion-implanted layer is a cleavage surface.   
   
   
       11 . A semiconductor device comprising:
 a sensor portion having one surface and including a sensor structure at a surface portion of the surface and a connection portion electrically connected to the sensor structure, the connection portion being located within a connection region on an outer region of the surface;   a cap portion having a first surface and a second surface opposite to the first surface; and   an ion-implanted layer disposed on the second surface of the cap portion, wherein   the surface of the sensor portion is joined to the first surface of the cap portion such that the sensor structure is sealed between the sensor portion and the cap portion and such that the connection region is exposed through the cap portion.   
   
   
       12 . The semiconductor device according to  claim 11 , wherein
 a surface of the ion-implanted layer is a cleavage surface.