Method and system for diamond-based oxygen sensor
A diamond based oxygen sensor is able to function in harsh environment conditions. The oxygen sensor includes a gateless field effect transistor including a synthetic, quasi-intrinsic, hydrogen-passivated, monocrystalline diamond layer exhibiting a 2-dimension hole gas effect. The oxygen sensor also includes a sensing layer comprising yttrium-stabilized zirconia deposited onto a surface of the gateless field effect transistor.
1. An oxygen sensor, comprising:
a diamond substrate;
a gateless field effect transistor (FET) connected to the diamond substrate, the FET including:
a synthetic diamond layer exhibiting a 2-dimension hole gas effect;
a first highly-doped p-type region;
a second highly-doped p-type region; and
a 2-dimension hole gas conductive channel between the first highly-doped p-type region and the second highly-doped p-type region; and
an oxygen-sensing layer including a yttrium-stabilized zirconia (YSZ) supported by the gateless FET.
2. The oxygen sensor of claim 1 , wherein:
the first highly-doped p-type region is implanted within the synthetic diamond layer; and
the second highly-doped p-type region is implanted within the synthetic diamond layer.
3. The oxygen sensor of claim 1 , the synthetic diamond layer including a quasi-intrinsic and hydrogen-passivated synthetic diamond layer.
4. The oxygen sensor of claim 1 , the gateless FET further including:
an ohmic source contact electrically coupled to the first highly-doped p-type region; and
an ohmic drain contact electrically coupled to the second highly-doped p-type region.
5. The oxygen sensor of claim 3 , wherein:
the oxygen-sensing layer is supported by the 2-dimension hole gas conductive channel and electrically coupled between the ohmic source contact and the ohmic drain contact.
6. The oxygen sensor of claim 1 , the diamond substrate including a polycrystalline diamond substrate.
7. The oxygen sensor of claim 6 , wherein the synthetic diamond layer is grown on a first side of the polycrystalline diamond substrate.
8. The oxygen sensor of claim 7 , the gateless FET further including an ohmic contact substrate supported by a second side of the polycrystalline diamond substrate.
9. The oxygen sensor of claim 2 , wherein:
the first highly-doped p-type region is implanted within the synthetic diamond layer using boron implantation; and
the second highly-doped p-type region is implanted within the synthetic diamond layer using boron implantation.
10. The oxygen sensor of claim 1 , wherein:
the 2-dimension hole gas conductive channel is formed within the synthetic diamond layer by performing hydrogen passivation.
11. The oxygen sensor of claim 4 , wherein the ohmic source contact and the ohmic drain contact are formed using a stack of Ti/Au.
12. A method of forming a gateless FET oxygen sensor, comprising:
forming a gateless field effect transistor (FET) connected to a diamond substrate, the FET including:
a synthetic diamond layer exhibiting a 2-dimension hole gas effect;
a first highly-doped p-type region;
a second highly-doped p-type region; and
a 2-dimension hole gas conductive channel between the first highly-doped p-type region and the second highly-doped p-type region; and
forming an oxygen-sensing layer including a yttrium-stabilized zirconia (YSZ) supported by the gateless FET.
13. The oxygen sensor of claim 12 , wherein forming the gateless FET includes growing the synthetic diamond layer on a first side of the diamond substrate, the diamond substrate including a polycrystalline diamond substrate.
14. The oxygen sensor of claim 12 , wherein forming the gateless FET further includes:
implanting the first highly-doped p-type region within the synthetic diamond layer; and
implanting the second highly-doped p-type region within the synthetic diamond layer.
15. The oxygen sensor of claim 12 , wherein generating the synthetic diamond layer includes generating a quasi-intrinsic, hydrogen-passivated monocrystalline diamond layer between the first highly-doped p-type region and the second highly-doped p-type region.
16. The oxygen sensor of claim 12 , wherein forming the gateless FET further includes:
disposing an ohmic source contact on the first highly-doped p-type region; and
disposing an ohmic drain contact on the second highly-doped p-type region.
17. The oxygen sensor of claim 12 , wherein forming the gateless FET further includes disposing an ohmic contact substrate on a second side of the diamond substrate.
18. The oxygen sensor of claim 12 , wherein the first highly-doped p-type region and the second highly-doped p-type region are generated within the synthetic diamond layer using boron implantation.
19. The oxygen sensor of claim 12 , wherein the 2-dimension hole gas conductive channel is generated within the synthetic diamond layer by performing hydrogen passivation.
20. The oxygen sensor of claim 16 , wherein the ohmic source contact and the ohmic drain contact are formed using a stack of Ti/Au.