Ferroelectric read head

Abstract

An apparatus can include a read head formed in a semiconductor layer of an air bearing surface, the read head comprising a channel region formed between a source and drain which are doped to a higher conductivity than the channel region; wherein the channel region is configured to generate a charge carrier depletion region in response to a first ferroelectric dipole direction, and to accumulate charge carriers in response to a second ferroelectric dipole direction.

1 . An apparatus, comprising:
 a read head formed in a semiconductor layer of an air bearing surface, the read head comprising
 a channel region formed between a source and drain which are doped to a higher conductivity than the channel region; wherein 
 the channel region is configured to generate a charge carrier depletion region in response to a first ferroelectric dipole direction, and to accumulate charge carriers in response to a second ferroelectric dipole direction. 
   
     
     
         2 . The apparatus of  claim 1 , wherein:
 the semiconductor layer comprises silicon.   
     
     
         3 . The apparatus of  claim 1 , wherein:
 the air bearing surface comprises a semiconductor-on-insulator structure comprising an insulating layer formed between the semiconductor layer and a semiconductor substrate portion.   
     
     
         4 . The apparatus of  claim 3 , wherein:
 the semiconductor layer and semiconductor substrate portion comprise silicon, and   the insulating layer comprises silicon dioxide.   
     
     
         5 . The apparatus of  claim 1 , further including:
 a write head configured to receive at least two different voltages, each corresponding to the formation of a different ferroelectric dipole direction.   
     
     
         6 . The apparatus of  claim 5 , wherein:
 the write head is formed over the channel region and separated from the read head by an insulating separation layer.   
     
     
         7 . The apparatus of  claim 5 , wherein:
 the write head is formed from a material selected from the group of: silicon, aluminum, gold, silver, platinum and copper.   
     
     
         8 . An apparatus, comprising:
 a read head comprising a semiconductor layer having regions with different doping densities, the read head configured to vary a current flow through a channel region between two doped regions in response to a direction of a ferroelectric dipole in proximity to the channel region.   
     
     
         9 . The apparatus of  claim 8 , wherein:
 the read head is configured to enable a first current flow between two doped regions in response to a first ferroelectric dipole orientation, and to enable a second current flow between the two doped regions in response to a second ferroelectric dipole orientation; wherein,   the first current is smaller than the second current.   
     
     
         10 . The apparatus of  claim 9 , wherein:
 the read head comprises the channel region, a source, and a drain, the source and drain being doped to a higher concentration than the channel region; wherein   the first and second currents flow between the source and drain through the channel region.   
     
     
         11 . The apparatus of  claim 10 , wherein:
 the read head comprises a portion of an air bearing surface having a bottom surface; and   the source, channel region, and drain are disposed adjacent to one another in a direction parallel to the bottom surface.   
     
     
         12 . The apparatus of  claim 8 , wherein:
 the read head comprises a portion of an air bearing surface having a bottom surface; and   the read head is separated from the bottom surface by at least one insulating layer.   
     
     
         13 . The apparatus of  claim 8 , further including:
 a write head configured to receive a plurality of voltages to establish a ferroelectric dipole direction in a ferroelectric medium.   
     
     
         14 . The apparatus of  claim 13 , wherein:
 the read head and write head comprise portions of an air bearing surface having a bottom surface; and   the read head is disposed between the bottom surface and the write head.   
     
     
         15 . A method, comprising:
 determining a data value stored by a ferroelectric medium according to a conductivity of a read head channel region formed between a source and drain; wherein   the conductivity of the channel region varies in response to an orientation of a ferroelectric dipole in proximity to the channel region.   
     
     
         16 . The method of  claim 15 , wherein:
 a current flowing through the channel region, between the source and drain, varies according to the orientation of the ferroelectric dipole.   
     
     
         17 . The method of  claim 15 , wherein:
 determining the data value includes positioning an air bearing surface comprising the read head over the ferroelectric medium.   
     
     
         18 . The method of  claim 15 , wherein:
 the channel region is depleted of charge carriers in response to the ferroelectric dipole having a first orientation, and accumulates the charge carriers in response to the ferroelectric dipole having a second orientation.   
     
     
         19 . The method of  claim 15 , further including:
 storing a data value in the ferroelectric medium according to a voltage applied to a write head positioned over the channel region.   
     
     
         20 . The method of  claim 19 , wherein:
 storing the data value includes positioning an air bearing surface comprising the write head and the read head over the ferroelectric medium.