Method for preparing substrate having monocrystalline film
Provided is a method for easily preparing a substrate comprising a monocrystalline film thereon or thereabove with almost no crystal defects without using a special substrate. More specifically, provided is a method for preparing a substrate comprising a monocrystalline film formed on or above a handle substrate, the method comprising: a step A of providing a donor substrate and the handle substrate; a step B of growing a monocrystalline layer on the donor substrate; a step C of implanting ions into the monocrystalline layer on the donor substrate so as to form an ion-implanted layer; a step D of bonding a surface of the monocrystalline layer of the ion-implanted donor substrate to a surface of the handle substrate; and a step E of peeling the bonded donor substrate at the ion-implanted layer existing in the monocrystalline layer so as to form the monocrystalline film on or above the handle substrate; wherein at least the steps A to E are repeated by using the handle substrate having the monocrystalline film formed thereon or thereabove as a donor substrate.
1. A method for preparing a substrate comprising a monocrystalline film formed on or above a handle substrate, the method comprising:
a step A of providing a donor substrate and the handle substrate;
a step B of growing a monocrystalline layer on the donor substrate;
a step C of implanting ions into the monocrystalline layer on the donor substrate so as to form an ion-implanted layer;
a step D of bonding a surface of the monocrystalline layer of the ion-implanted donor substrate to a surface of the handle substrate; and
a step E of peeling the bonded donor substrate at the ion-implanted layer existing in the monocrystalline layer so as to form the monocrystalline film on or above the handle substrate;
wherein at least the steps A to E are repeated by using the handle substrate having the monocrystalline film formed thereon or thereabove as a donor substrate.
2. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step E of peeling comprises peeling the bonded donor substrate at the ion-implanted layer by using a heat treatment or mechanical means.
3. The method for preparing a substrate comprising a monocrystalline film according to claim 1 or 2 , wherein said step C of implanting comprises implanting hydrogen ions and/or noble gas ions.
4. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step D of bonding comprises bonding the surface of the monocrystalline layer which the surface has been smoothened to the surface of the handle substrate.
5. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein a surface of the monocrystalline film on or above the handle substrate obtained in said step E of peeling is smoothened after said step E.
6. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step B of growing comprises a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process or a liquid phase epitaxial growing process.
7. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said donor substrate or said handle substrate comprises silicon, sapphire, SiC, GaN, AlN or zinc oxide.
8. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step A of providing comprises providing the handle substrate being selected from the group consisting of an amorphous substrate, a polycrystalline substrate and a monocrystalline substrate, and having surface roughness (Ra) of 0.5 nm or less for the surface to be bonded in the step D.
9. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step A of providing comprises providing the donor substrate and/or the handle substrate comprising one or more buffer layers selected from the group consisting of SiO 2 , Si 3 N 4 , GaN, AlGaN, InGaN, AlN and combinations thereof.
10. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step B of growing comprises growing the monocrystalline layer of any of silicon, SiC, GaN, AlN, zinc oxide and diamond.
11. The method for preparing a substrate comprising a monocrystalline film according to claim 1 , wherein said step D of bonding comprises bonding said surface of the monocrystalline layer to said surface of the handle substrate, one or both of said surfaces having been subjected to a plasma treatment.
12. A method for preparing a substrate comprising a monocrystalline layer thereon, comprising a step of growing a monocrystalline layer on a monocrystalline film on the substrate prepared in the method according to claim 1 .
13. The method for preparing a substrate comprising a monocrystalline layer according to claim 12 , further comprising a step of annealing the substrate comprising the grown monocrystalline layer.
14. A method for preparing a self-sustained monocrystalline film, comprising steps of:
implanting ions into the monocrystalline layer of the substrate prepared in the method according to claim 12 or 13 so as to form an ion-implanted layer, and
peeling at the ion-implanted layer to obtain the self-sustained monocrystalline film.
15. The method for preparing a self-sustained monocrystalline film according to claim 14 , further comprising a step of annealing said self-sustained monocrystalline film obtained in said step of peeling.
16. A method for preparing a monocrystal, comprising a step of using the substrate comprising a monocrystalline film, the substrate comprising a monocrystalline layer, or the self-sustained monocrystalline film prepared in the method according to claim 1 as a seed substrate for epitaxial growth or bulk crystal growth.