Graphene sensor

Abstract

A method for forming a sensor includes forming a channel in substrate, forming a sacrificial layer in the channel, forming a sensor having a first dielectric layer disposed on the substrate, a graphene layer disposed on the first dielectric layer, and a second dielectric layer disposed on the graphene layer, a source region, a drain region, and a gate region, wherein the gate region is disposed on the sacrificial layer removing the sacrificial layer from the channel.

1 . A method for forming a sensor, the method comprising:
 forming a channel in substrate;   forming a sacrificial layer in the channel;   forming a sensor having a first dielectric layer disposed on the substrate, a graphene layer disposed on the first dielectric layer, and a second dielectric layer disposed on the graphene layer, a source region, a drain region, and a gate region, wherein the gate region is disposed on the sacrificial layer; and   removing the sacrificial layer from the channel.   
     
     
         2 . The method of  claim 1 , wherein the method further includes disposing a capping layer on the sensor, the substrate, and the sacrificial layer prior to removing the sacrificial layer from the channel. 
     
     
         3 . The method of  claim 2 , wherein the method further includes removing portions of the capping layer to expose the source region, the drain region, the gate region, and a portion of the sacrificial layer prior to removing the sacrificial layer from the channel. 
     
     
         4 . The method of  claim 1 , wherein the graphene layer includes a graphene tube. 
     
     
         5 . The method of  claim 1 , wherein the sacrificial layer includes SiGe. 
     
     
         6 . The method of  claim 1 , wherein a longitudinal axis of the sensor is arranged orthogonally to a longitudinal axis of the channel. 
     
     
         7 . The method of  claim 1 , wherein the substrate is a buried oxide (BOX) substrate. 
     
     
         8 . A method for forming a sensor, the method comprising:
 forming a channel substrate;   forming a sacrificial layer in the channel;   forming a first dielectric layer on the substrate and the sacrificial layer;   forming a graphene layer on the first dielectric layer;   forming a second dielectric layer on the graphene layer;   removing portions of the second dielectric layer and portions of the graphene layer to expose a first portion of the first dielectric layer and a second portion of the first dielectric layer;   forming a source region on the exposed first portion of the first dielectric layer and drain region on the second portion of the first dielectric layer;   forming a capping layer on the exposed substrate, graphene layer, source region, drain region, and second dielectric layer;   removing portions of the capping layer to expose the source region, drain region, the second dielectric layer, and portions of the sacrificial layer; and   removing the sacrificial layer from the channel.   
     
     
         9 . The method of  claim 8 , wherein the graphene layer includes a graphene tube. 
     
     
         10 . The method of  claim 8 , wherein a longitudinal axis of the sensor is arranged orthogonally to a longitudinal axis of the channel. 
     
     
         11 . The method of  claim 8 , wherein the exposed portions of the sacrificial layer are arranged at opposing distal ends of the sacrificial layer. 
     
     
         12 . The method of  claim 8 , wherein the removing portions of the capping layer to expose the source region, drain region, the second dielectric layer, and portions of the sacrificial layer forms a first cavity in the capping layer defined by the source region and the capping layer, a second cavity in the capping layer defined by the drain region and the capping layer, a third cavity in the capping layer defined by the sacrificial layer and the capping layer, and a fourth cavity in the capping layer defined by the sacrificial layer and the capping layer. 
     
     
         13 . The method of  claim 8 , wherein the removal of the sacrificial layer increases the depth of the third cavity such that the third cavity is defined by a first distal end of the channel and the capping layer, and increases the depth of the fourth cavity such that the fourth cavity is defined by a second distal end of the channel and the capping layer. 
     
     
         14 . The method of  claim 13 , wherein the third cavity is communicative with the fourth cavity. 
     
     
         15 . The method of  claim 13 , wherein the removal of the sacrificial layer forms a flow path defined by the third cavity, the channel, the first dielectric layer and the fourth cavity. 
     
     
         16 . The method of  claim 13 , wherein the substrate is a buried oxide (BOX) substrate. 
     
     
         17 . A sensor comprising:
 a first dielectric layer disposed on a substrate;   a graphene layer disposed on the first dielectric layer;   a second dielectric layer disposed on the graphene layer;   a source region disposed on the first dielectric layer;   a drain region disposed on the first dielectric layer;   a capping layer disposed on a portion of the substrate; and   a flow path defined by a channel in the substrate, a first cavity in the capping layer communicative with the channel, the first dielectric layer, and a second cavity in the capping layer communicative with the channel.   
     
     
         18 . The sensor of  claim 17 , wherein the sensor includes a gate region. 
     
     
         19 . The sensor of  claim 17 , wherein the graphene layer includes a graphene tube. 
     
     
         20 . The sensor of  claim 17 , wherein the second dielectric layer has a greater thickness than the first dielectric layer.