Method of bonding substrates utilizing a substrate holder with holding fingers

1. A substrate bonding method, comprising:

arranging a substrate susceptor to hold a first substrate thereon;

arranging a substrate holder to hold a second substrate thereon such that the first and second substrates are aligned with each other, the substrate holder including a plurality of holding fingers configured to hold an edge of the second substrate and move independently from each other;

bringing a center of the second substrate to contact the first substrate;

allowing a spontaneous bonding propagation between the first substrate and the second substrate to occur;

bringing the second substrate closer to the first substrate while holding the edge of the second substrate; and

releasing the holding of the edge of the second substrate.

2. The substrate bonding method as claimed in claim 1 , wherein bringing the second substrate close to the first substrate includes independently controlling the plurality of holding fingers to move toward the first substrate.

3. The substrate bonding method as claimed in claim 1 , further comprising:

measuring a distance between an edge of the first substrate and the edge of the second substrate using a distance sensor,

wherein a movement of each of the plurality of holding fingers is controlled based on the distance sensed by the distance sensor.

4. The substrate bonding method as claimed in claim 3 , further comprising:

calculating a target location of each of the plurality of holding fingers based on the distance sensed by the distance sensor; and

moving each of the plurality of holding fingers to the target location.

5. The substrate bonding method as claimed in claim 3 , wherein releasing the holding of the edge of the second substrate includes releasing the holding of the edge of the second substrate when the distance between the edge of the second substrate and the edge of the first substrate is about 1 μm to about 50 μm.

6. The substrate bonding method as claimed in claim 1 , wherein bringing the second substrate closer to the first substrate includes bonding the edge of the second substrate to an edge of the first substrate.

7. The substrate bonding method as claimed in claim 1 , wherein, in bringing the second substrate closer to the first substrate, distances by which the plurality of holding fingers move, respectively, are not equal to each other.

8. The substrate bonding method as claimed in claim 1 , further comprising:

adjusting an orientation of the second substrate such that the first substrate and the second substrate are parallel to each other, before allowing the center of the second substrate to contact the first substrate,

wherein the orientation of the second substrate is adjusted such that the second substrate is parallel to the first substrate, by independently controlling the plurality of holding fingers.

9. The substrate bonding method as claimed in claim 1 , wherein the plurality of holding fingers are to hold the second substrate on respective ends of the plurality of holding fingers by an attraction formed on the respective ends of the plurality of holding fingers.

10. The substrate bonding method as claimed in claim 9 , wherein each of the plurality of holding fingers has a fluid passage that communicates with each of the respective ends of the plurality of holding fingers, the attraction being formed by maintaining an internal pressure of the fluid passage to be lower than an ambient pressure.

11. The substrate bonding method as claimed in claim 9 , wherein:

the plurality of holding fingers are to hold the second substrate on respective ends of the plurality of holding fingers via an electrostatic attraction, and

the plurality of holding fingers are to apply an electrostatic force to the second substrate and release the electrostatic force from the second substrate to control application of the electrostatic attraction.

12. The substrate bonding method as claimed in claim 1 , wherein bringing the center of the second substrate to contact the first substrate includes pressing a central portion of the second substrate toward the first substrate with a pressing finger provided in the substrate holder.

13. The substrate bonding method as claimed in claim 12 , wherein:

the substrate susceptor includes a plurality of susceptor holding fingers configured to hold the first substrate, and

bringing the second substrate closer to the first substrate includes independently controlling the plurality of susceptor holding fingers to move toward the second substrate.

14. The substrate bonding method as claimed in claim 13 , wherein bringing the center of the second substrate to contact the first substrate includes pressing a central portion of the first substrate toward the second substrate with a susceptor pressing finger provided in the substrate susceptor.

15. The substrate bonding method as claimed in claim 1 , wherein the first substrate and the second substrate are single crystal substrates.

16. A substrate bonding method, comprising:

arranging a substrate susceptor to hold a first substrate thereon;

arranging a substrate holder to hold a second substrate thereon such that the first substrate and the second substrate are aligned with each other, the substrate holder including a plurality of holding fingers configured to hold an edge of the second substrate and move independently from each other;

measuring a distance between an edge of the first substrate and the edge of the second substrate using a distance sensor;

bringing a center of the second substrate to contact the first substrate;

moving the plurality of holding fingers toward the first substrate while holding the edge of the second substrate; and

releasing the holding of the edge of the second substrate,

wherein each of the plurality of holding fingers is controlled based on the distance sensed by the distance sensor.

17. The substrate bonding method as claimed in claim 16 , wherein a target position and a speed of each of the plurality of holding fingers are determined based on the distance sensed by the distance sensor.

18. The substrate bonding method as claimed in claim 16 , wherein:

the substrate susceptor includes a plurality of susceptor holding fingers configured to hold the first substrate, and

the substrate bonding method further comprises moving the plurality of susceptor holding fingers toward the second substrate while the plurality of holding fingers move toward the first substrate.

19. The substrate bonding method as claimed in claim 16 , wherein bringing the center of the second substrate to contact the first substrate includes:

pressing a central portion of the second substrate toward the first substrate with a pressing finger provided in the substrate holder; and

pressing a central portion of the first substrate toward the second substrate with a susceptor pressing finger provided in the substrate susceptor.

20. A substrate bonding method, comprising:

arranging a substrate susceptor to hold a first substrate thereon;

arranging a substrate holder to hold a second substrate thereon such that the first and second substrates are aligned with each other, the substrate holder including a plurality of holding fingers configured to hold an edge of the second substrate and move independently from each other;

measuring a distance between an edge of the first substrate and the edge of the second substrate using a distance sensor;

bringing a center of the second substrate to contact the first substrate;

allowing a spontaneous bonding propagation between the first substrate and the second substrate to occur while holding the edge of the second substrate;

moving the plurality of holding fingers toward the first substrate while holding the edge of the second substrate; and

releasing the holding of the edge of the second substrate,

wherein each of the plurality of holding fingers is controlled based on the distance sensed by the distance sensor.