Cellular electrophysiology sensor chip and cellular electrophysiology sensor using the chip, and method of manufacturing cellular electrophysiology sensor chip

Abstract

A cellular electrophysiology sensor is adapted to measure an electrical change of a test cell. A chip for the sensor includes a diaphragm, and a thermally-oxidized film mainly containing silicon dioxide on the diaphragm. The diaphragm includes a silicon layer and a silicon dioxide layer on an upper surface of the silicon layer. A through-hole passing through the silicon layer and the silicon dioxide layer is formed. The through-hole has an opening which opens at the silicon dioxide layer and is adapted to capture the test cell. The thermally-oxidized film is provided on an inner wall surface of the through-hole, and unified with the silicon dioxide layer at the opening of the through-hole. This cellular electrophysiology sensor chip can stably capture the test cell and provides a gigaseal stably even if test cells have different properties,

1 . A chip for a cellular electrophysiology sensor for measuring an electrical change of a test cell, comprising:
 a diaphragm including a silicon layer and a silicon dioxide layer provided on an upper surface of the silicon layer, the diaphragm having a through-hole passing through the silicon layer and the silicon dioxide layer, the through-hole having an opening which opens at the silicon dioxide layer and which is adapted to capture the test cell; and   a thermally-oxidized film provided on an inner wall surface of the through-hole, the thermally-oxidized film is a film melting and being unified with the silicon dioxide layer at the opening of the through-hole, the thermally-oxidized film mainly containing silicon dioxide.   
     
     
         2 . The chip according to  claim 1 , wherein: the silicon dioxide layer is connected to the thermally-oxidized film via a smooth surface. 
     
     
         3 . The chip according to  claim 1 , wherein: the silicon dioxide layer is connected to the thermally-oxidized film via a continuously-curved surface. 
     
     
         4 . The chip according to  claim 1 , wherein: the silicon dioxide layer has a thickness not smaller than 0.3 μm. 
     
     
         5 . The chip according to  claim 1 , wherein: the thermally-oxidized film has a thickness ranging from 100 to 2000 nm. 
     
     
         6 . The chip according to  claim 1 , wherein: the through-hole has an inner diameter gradually increasing from an inside of the through-hole toward the opening. 
     
     
         7 . The chip according to  claim 1 , wherein: the thermally-oxidized film covers a surface of the diaphragm. 
     
     
         8 . The chip according to  claim 1 , further comprising a supporter provided at an outer periphery of the diaphragm. 
     
     
         9 . A cellular electrophysiology sensor for measuring an electrical change of a test cell, comprising:
 a chip including
 a diaphragm including a silicon layer and a silicon dioxide layer provided on an upper surface of the silicon layer, the diaphragm having a through-hole passing through the silicon layer and the silicon dioxide layer, the through-hole opening in the silicon dioxide layer and having an opening adapted to capture the test cell, and 
 a thermally-oxidized film provided on an inner wall surface of the through-hole, the thermally-oxidized film is a film melting and being unified with the silicon dioxide layer at the opening of the through-hole, the thermally-oxidized film mainly containing silicon dioxide; 
   a first electrode bath provided on an upper surface of the diaphragm;   a first electrode provided in the first electrode bath;   a second electrode bath provided on a lower surface of the diaphragm, the second electrode bath communicating with the first electrode bath via the through-hole; and   a second electrode provided in the second electrode bath.   
     
     
         10 . A method of manufacturing a chip for a cellular electrophysiology sensor, comprising:
 providing a wafer having a silicon layer and a silicon dioxide layer provided on an upper surface of the silicon layer;   forming a through-hole passing through the silicon layer and the silicon dioxide layer of the wafer, the through-hole having an opening which opens at the silicon dioxide layer;   forming a thermally-oxidized film mainly containing silicon dioxide on a portion of the silicon layer located on an inner wall surface of the through-opening; and   melting the thermally-oxidized film and the silicon dioxide layer to unify the thermally-oxidized film with the silicon dioxide layer at the opening.   
     
     
         11 . The method according to  claim 10 , further comprising
 forming a recess extending from the inner wall surface of the through-hole along a lower surface of the silicon dioxide layer such that a portion of the silicon dioxide layer protrudes from the recess, wherein   said melting the thermally-oxidized film and the silicon dioxide layer to unify the thermally-oxidized film with the silicon dioxide layer comprises melting the protruding portion of the silicon dioxide layer and the thermally-oxidized film to unify the protruding portion of the silicon dioxide layer with the thermally-oxidized film at the opening.