Method of fabricating hafnium oxide layer and semiconductor device having the same
Provided are a method of fabricating a hafnium oxide layer and a method of fabricating a semiconductor device using the same. The method of fabricating a tetragonal hafnium oxide layer includes providing a substrate and then forming an initial hafnium oxide layer on the substrate. The initial hafnium oxide layer may have an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof on the substrate. Phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer at a temperature equal to or higher than a phase change temperature to the tetragonal hafnium oxide layer, is performed. Then, the heated tetragonal hafnium oxide layer may be rapidly cooled to suppress nucleation and growth of a monoclinic hafnium oxide in the tetragonal hafnium oxide layer.
1. A method for fabricating a tetragonal hafnium oxide layer, the method comprising:
forming an initial hafnium oxide layer over a substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer to a phase change temperature; and
rapid-cooling the tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide layer,
wherein the rapid-cooling of the tetragonal hafnium oxide layer is performed by a descending temperature time-temperature path,
wherein the nucleation and growth of the monoclinic hafnium oxide has a Martensite-like transformation behavior, and the Martensite-like transformation behavior has a time-temperature-transformation curve of initiation of crystallization of a monoclinic hafnium oxide, and
wherein the descending temperature time-temperature path is within a left outside region of the curve.
2. The method of claim 1 , wherein the initial hafnium oxide layer is formed over the substrate by atomic layer deposition, chemical vapor deposition, physical vapor deposition, or a combination thereof.
3. The method of claim 1 , wherein a thickness of the initial hafnium oxide layer is in a range between 20 Å and 200 Å.
4. The method of claim 1 , wherein the phase-changing to the tetragonal hafnium oxide layer is performed by a rapid laser annealing process.
5. The method of claim 4 , wherein the rapid laser annealing process is performed using a laser spike annealing process, a flash lamp annealing process, a diode laser annealing process, or a combination thereof.
6. The method of claim 1 , wherein the rapid-cooling of the tetragonal hafnium oxide layer is performed by cooling the tetragonal hafnium oxide layer down to a temperature T 2 for an elapsed time D 2 , and
wherein a phase change based on a Martensite-like transformation of the monoclinic hafnium oxide does not occur during the rapid-cooling.
7. The method of claim 1 , wherein the rapid-cooling starts at a first temperature X 1 and at a first given time Y 1 and completes at a second temperature X 2 and at a second given time Y 2 ,
wherein the phase-changing of the initial hafnium oxide layer to the tetragonal hafnium oxide layer occurs at a third temperature X 3 and at a third give time Y 3 ,
wherein Y 3 is variable depending on X 3 and a relation between X 3 and Y 3 is defined by a function Y 3 =f(X 3 ),
wherein Y 1 is variable depending on X 1 and Y 2 is variable depending on X 2 , and
wherein X 1 , Y 1 , X 2 , and Y 2 are selected so that Y 1 <f(X 1 ) and Y 2 <f(X 2 ) are satisfied.
8. The method of claim 1 , wherein the rapid-cooling is performed for 10 ms or less.
9. The method of claim 1 , wherein the rapid-cooling is performed at a speed between 10 3 ° C./sec and 10 6 ° C./sec.
10. The method of claim 1 , further comprising heating the rapidly cooled tetragonal hafnium oxide layer to a temperature T 3 ,
wherein a lowest temperature at which the phase-changing can occur is T 4 . and wherein the temperature T 3 is lower than the temperature T 4 .
11. The method of claim 1 , further comprising forming an additional layer over the tetragonal hafnium oxide layer, and
wherein the additional layer includes a silicon oxide (SiO 2 ) layer, a silicon nitride (SiN) layer, a zirconium oxide (ZrO 2 ) layer, a tantalum oxide (Ta 2 O-5) layer, a titanium oxide (TiO 2 ) layer, an aluminum oxide (Al 2 O 3 ) layer, lanthanum oxide (La 2 O 3 ) layer, an yttrium oxide (Y 2 O 3 ) layer, a zirconium oxide (ZrO 2 ) layer, a strontium titanium oxide (SrTiO 3 ) layer, a zirconium silicon oxide (ZrSiO 4 ) layer, a hafnium zirconium oxide (HfZrO 4 ) layer, a strontium bismuth tantalum oxide (SrBi 2 Ta 2 O 9 , SBT) layer, a lead zirconium titanium oxide (PbZr x Ti 1-x O 3 , PZT) layer, barium strontium titanium oxide (Ba x Sr 1-x TiO 3 , BST) layer, or a stacked structure thereof.
12. A method for fabricating a tetragonal hafnium oxide layer, the method comprising:
forming an initial hafnium oxide layer over a substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
heat-treating the initial hafnium oxide layer at a temperature T 1 , wherein the temperature T 1 is lower than a phase change temperature;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer to the phase change temperature;
rapid-cooling the tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide.
13. A method for fabricating a tetragonal hafnium oxide layer, the method comprising:
forming an initial hafnium oxide layer over a substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer to a phase change temperature: and
rapid-cooling the tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide layer,
wherein the phase-changing of the initial hafnium oxide layer to the tetragonal hafnium oxide layer is performed by heating the initial hafnium oxide layer at a speed S 1 for an effective heating time D 1 ,
wherein the speed S 1 is in a range between 150° C./sec and 5×108° C./sec, and
wherein the effective heating time period D 1 is between 0.05 μs and 2×104 μs.
14. The method of claim 13 , wherein the phase change temperature is between 800° C. and 1,600 ° C. during the effective heating time.
15. The method of claim 13 , wherein the phase-changing is performed in an inert gas atmosphere.
16. A method for fabricating a tetragonal hafnium oxide layer, the method comprising:
forming an initial hafnium oxide layer over a substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
forming a nucleation suppressing layer over the initial hafnium oxide layer;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer to a phase change temperature; and
rapid-cooling the tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide layer based on the nucleation suppressing layer.
17. The method of claim 16 , wherein the nucleation suppressing layer restricts a volume expansion due to the change of the tetragonal hafnium oxide layer into the monoclinic hafnium oxide.
18. The method of claim 16 , wherein the nucleation suppressing includes a titanium nitride (TiN), a tantalum nitride (TaN), titanium aluminum nitride (TiAlN), titanium silicon nitride (TiSiN), tantalum carbonate (TaC), zirconium nitride (ZrN), hafnium nitride (HfN), ruthenium (Ru), or a stacked structure thereof.
19. The method of claim 16 , wherein the nucleation suppressing layer comprises an aluminum oxide, a zirconium oxide, a tantalum oxide, or a titanium oxide.
20. The method of claim 16 , wherein the nucleation suppressing layer is doped with aluminum or silicon.
21. The method of claim 20 , wherein a doping concentration of the aluminum or the silicon in the nucleation suppressing layer is within a range between 0.05 weight % and 5weight % with respect to a total weight of the nucleation suppressing layer.
22. A method of fabricating a semiconductor device, the method comprising:
providing a substrate;
forming an initial hafnium oxide layer over the substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer at a temperature equal to or higher than a phase change temperature of the tetragonal hafnium oxide layer;
rapid-cooling the heated tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide layer; and
forming an electrode or a semiconductor layer over the tetragonal hafnium oxide layer,
wherein the rapid-cooling of the tetragonal hafnium oxide layer is performed by a descending temperature time-temperature path,
wherein the nucleation and growth of the monoclinic hafnium oxide has a Martensite-like transformation behavior, and the Martensite-like transformation behavior has a time-temperature-transformation curve of initiation of crystallization of a monoclinic hafnium oxide, and
wherein the descending temperature time-temperature path is within a left outside region of the curve.
23. The method of claim 22 , wherein the tetragonal hafnium oxide layer serves as a dielectric of a capacitor or a gate insulation layer.
24. A method of fabricating a semiconductor device, the method comprising:
providing a substrate;
forming an initial hafnium oxide layer over the substrate, wherein the initial hafnium oxide layer has an amorphous structure, a monoclinic crystal structure, or a mixed structure thereof;
forming a nucleation suppressing layer over the initial hafnium oxide layer;
phase-changing the initial hafnium oxide layer to a tetragonal hafnium oxide layer by heating the initial hafnium oxide layer at a temperature equal to or higher than a phase change temperature of the tetragonal hafnium oxide layer;
rapid-cooling the heated tetragonal hafnium oxide layer to suppress a nucleation and growth of a monoclinic hafnium oxide from the tetragonal hafnium oxide layer based on the nucleation suppressing layer; and
forming an electrode or a semiconductor layer over the tetragonal hafnium oxide layer.