Process for preparing zinc oxide films containing p-type dopant
AssigneeThe Curators of the University of Missouri
InventorsHenry W. White, Shen Zhu, Yungryel Ryu
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Abstract
A p-type zinc oxide film and a process for preparing the film is disclosed. In a preferred embodiment, the p-type zinc oxide film contains arsenic and is grown on a gallium arsenide substrate. The p-type zinc oxide film has a net acceptor concentration of at least about 1015 acceptors/cm3, a resistivity of no greater than about 1 ohm-cm, and a Hall mobility of between about 0.1 and about 50 cm2/Vs.
Claims24
A process for growing an arsenic doped ZnO film on a GaAs substrate in a pulsed laser deposition chamber, the process comprising:
- cleaning the GaAs substrate;
- adjusting the temperature in the pulsed laser deposition chamber to between about 300° C. to about 450° C.;
- pre-ablating a polycrystalline ZnO crystal;
- directing an excimer pulsed laser beam onto the polycrystalline ZnO crystal to grow a ZnO film on the GaAs substrate;
- increasing the temperature of the pulsed laser deposition chamber to between about 450° C. and about 600° C.;
- and
- annealing the ZnO coated GaAs substrate to diffuse at least about 1×1018 acceptors/cm3 from the GaAs into the ZnO film to produce the arsenic doped ZnO film.
A process for growing a p-type ZnO film on a substrate, the process comprising:
- cleaning the substrate;
- adjusting the temperature in the pulsed laser deposition chamber to between about 300° C. and about 450° C.;
- and
- growing a p-type ZnO film on the substrate by directing an excimer pulsed laser beam onto a pressed ZnO powder pellet containing a p-type dopant to grow the p-type ZnO film containing at least about 1018 acceptors/cm3 on the substrate.
A process for preparing a p-n junction having a p-type ZnO film and an n-type film wherein the net acceptor concentration is at least about 1018 acceptors/cm3, the process comprising:
- cleaning a substrate;
- adjusting the temperature in the pulsed laser deposition chamber to between about 300° C. to about 450° C.;
- growing a p-type ZnO film on the substrate by directing an excimer pulsed laser beam onto a pressed ZnO powder pellet containing a p-type dopant element to grow a p-type ZnO film containing at least about 1018 acceptors/cm3 on the substrate;
- and
- growing an n-type film on top of the p-type ZnO film by directing an excimer pulsed laser beam onto a pressed powder pellet containing an n-type dopant element to grow an n-type film on the p-type ZnO film on the substrate.
A process for preparing a p-n junction having a p-type ZnO film and an n-type film wherein the net acceptor concentration is at least about 1018 acceptors/cm3, the process comprising:
- cleaning a substrate;
- adjusting the temperature in the pulsed laser deposition chamber to between about 300° C. to about 450° C.;
- growing an n-type film on top of the substrate by directing an excimer pulsed laser beam onto a pressed powder pellet containing an n-type dopant element to grow an n-type film on the substrate;
- growing a p-type ZnO film on the n-type film by directing an excimer pulsed laser beam onto a pressed ZnO powder pellet containing a p-type dopant element to grow a p-type ZnO film containing at least about 1018 acceptors/cm3 on the n-type film.
A process for cleaning a substrate in a chamber prior to growing a film on the substrate, the process comprising:
- loading the substrate into the chamber and adjusting the temperature in the chamber to between about 400° C. and about 500° C.;
- filling the chamber with hydrogen to create a pressure in the chamber of between about 0.5 and about 3 Torr;
- adjusting the distance between a metal shutter in the chamber and the substrate to between about 3 to about 6 centimeters;
- and
- directing an excimer pulsed laser beam having an intensity of between about 20 to about 70 mJ and a repetition of between about 10 to about 30 Hz into the chamber for a period of between about 5 and about 30 minutes to illuminate the metal shutter and clean the substrate.
Dependencies are inferred from the claim text.