Bonding apparatus and bonding method

1 . A bonding apparatus configured to prepare a combined substrate by bonding a first substrate and a second substrate,

wherein the first substrate comprises a base substrate, and a device layer formed on a surface of the base substrate facing the second substrate,

wherein the bonding apparatus comprises:

a first holder configured to hold the first substrate;

a second holder configured to hold the second substrate;

a moving unit configured to move the first holder and the second holder relative to each other; and

a controller configured to:

control the first holder and the second holder to bond the first substrate and the second substrate to form the combined substrate within the bonding apparatus,

after the controlling of the first holder and the second holder to bond the first substrate and the second substrate to form the combined substrate within the bonding apparatus, control a thickness detector, which is configured to measure a total thickness of the combined substrate, to measure the total thickness at multiple points within the bonding apparatus,

wherein the thickness detector is fixed to a side surface of the first holder other than a holding surface of the first holder, or a side surface of the second holder other than a holding surface of the second holder, and

wherein the controller controls the moving unit to change a measurement point of the thickness detector among the multiple points.

2 . The bonding apparatus of claim 1 , further comprising:

a total thickness storage configured to store therein data measured by the controller.

3 . The bonding apparatus of claim 1 , further comprising:

a base thickness measurement controller configured to control a thickness detector, which is configured to measure a thickness of the base substrate, to measure the thickness of the base substrate at the multiple points.

4 . The bonding apparatus of claim 3 , further comprising:

a residual thickness calculator configured to calculate a thickness of a remainder of the combined substrate except the base substrate at the multiple points from the data measured by the controller and data measured by the base thickness measurement controller.

5 . The bonding apparatus of claim 4 , further comprising:

a residual thickness transmitter configured to transmit data calculated by the residual thickness calculator to an outside of the bonding apparatus.

6 . The bonding apparatus of claim 5 ,

wherein the residual thickness transmitter transmits the data calculated by the residual thickness calculator to a grinding apparatus configured to grind the base substrate.

7 . The bonding apparatus of claim 6 ,

wherein the residual thickness transmitter transmits the data calculated by the residual thickness calculator to the grinding apparatus via a server.

8 . The bonding apparatus of claim 3 , further comprising:

a base thickness transmitter configured to transmit data measured by the base thickness measurement controller to an outside of the bonding apparatus.

9 . The bonding apparatus of claim 1 , further comprising:

a total thickness transmitter configured to transmit data measured by the controller to an outside of the bonding apparatus.

10 . The bonding apparatus of claim 1 ,

wherein the thickness detector configured to measure the total thickness comprises a laser displacement meter.

11 . The bonding apparatus of claim 1 ,

wherein the thickness detector configured to measure the total thickness comprises a camera, and

the controller measures the total thickness by focusing of the camera.

12 . The bonding apparatus of claim 1 ,

wherein the second holder or the first holder has a holding surface configured to hold thereon the combined substrate,

wherein the controller performs:

measuring, at the multiple points, a position of the holding surface in a direction orthogonal to the holding surface in a state that the holding surface is exposed;

measuring, at the multiple points, a position of a surface of the combined substrate in the direction orthogonal to the holding surface in a state that the combined substrate is held on the holding surface; and

calculating, at the multiple points, the total thickness from a difference between the position of the holding surface and the position of the surface of the combined substrate in the direction orthogonal to the holding surface.

13 . The bonding apparatus of claim 12 ,

wherein the second holder or the first holder includes, on the holding surface, a suction hole configured to suck the combined substrate, and

the multiple points are disposed on the holding surface to be located at positions that are not overlapped with the suction hole.

14 . The bonding apparatus of claim 13 ,

wherein the second holder or the first holder includes a rib forming a flat surface on the holding surface, and

the multiple points lie on the flat surface of the rib.

15 . The bonding apparatus of claim 14 ,

wherein at least a portion of the flat surface of the rib is formed in a straight line shape or an annular shape.

16 . The bonding apparatus of claim 1 ,

wherein the second holder or the first holder includes a rib forming a flat surface on the holding surface,

wherein the multiple points lie on the flat surface of the rib,

wherein at least a portion of the flat surface of the rib is formed in an annular shape, and

wherein the bonding apparatus further comprises a rotating unit configured to rotate the holding surface.

17 . A bonding method of preparing a combined substrate by bonding a first substrate and a second substrate by using a bonding apparatus,

wherein the first substrate comprises a base substrate, and a device layer formed on a surface of the base substrate facing the second substrate,

wherein the bonding method comprises:

holding the first substrate with a first holder;

holding the second substrate with a second holder;

controlling a moving unit configured to move the first holder and the second holder relative to each other to align the first substrate and the second substrate;

controlling the first holder and the second holder to bond the first substrate and the second substrate to form the combined substrate within the bonding apparatus;

after bonding of the first substrate and the second substrate, measuring a total thickness of the combined substrate at multiple points within the bonding apparatus; and

measuring a thickness of the base substrate at the multiple points,

wherein the thickness of the base substrate is measured by a thickness detector that radiates light from above the base substrate, and measures the thickness of the base substrate from a phase difference between the light reflected from a top surface of the base substrate and the light reflected from the bottom surface of the base substrate, and

wherein the thickness detector is fixed to a side surface of the first holder other than a holding surface of the first holder, or a side surface of the second holder other than a holding surface of the second holder.

18 . The bonding method of claim 17 ,

wherein the thickness of the base substrate at the multiple points is measured in a state that the combined substrate is held by the second holder or the first holder.

19 . The bonding method of claim 18 , further comprising: calculating a thickness of a remainder of the combined substrate except the base substrate by calculating, at each of the multiple points, a difference between the total thickness of the combined substrate and the thickness of the base substrate.

20 . The bonding apparatus of claim 1 ,

wherein the thickness detector is configured to:

measure, at the multiple points, a position of a holding surface of the second holder holding the combined substrate after bonding; and

measure, at the multiple points, a position of a surface of the combined substrate opposite to the holding surface of the second holder while the combined substrate is held by the second holder, and

wherein the controller is configured to set the total thickness of the combined substrate as a difference between the measured position of the surface of the combined substrate opposite to the holding surface and the measured position of the holding surface.

21 . The bonding apparatus of claim 20 ,

wherein the thickness detector configured to measure the total thickness comprises a laser displacement meter, and

wherein the thickness detector is further configured to measure a distance to the holding surface from the laser displace meter.

22 . The bonding apparatus of claim 20 ,

wherein the thickness detector configured to measure the total thickness comprises a camera,

wherein the controller measures the total thickness by focusing of the camera,

wherein the controller is configured to:

focus the camera on the holding surface of the second holder in a state that the holding surface is exposed and store a height position of the second holder at the time of the focusing;

focus the camera on the surface of the combined substrate opposite to the holding surface in a state that the combined substrate is held by the second holder and store a height position of the second holder at the time of the focusing; and

calculate the total thickness of the combined substrate based on a shift amount between the stored positions, and

wherein the focusing of the camera includes moving the first holder or moving the second holder.