Wafer processing method

1. A method of processing a wafer having a plurality of identical pattern regions periodically formed on a top surface, the identical pattern regions each including a plurality of planned dividing lines intersecting each other and device regions demarcated by the plurality of planned dividing lines, wherein a plurality of metallic patterns are formed on the planned dividing lines, the method comprising:

a holding step of holding an undersurface side of the wafer on a holding table;

an imaging step of imaging a plurality of positions on the top surface of the wafer while moving the holding table and an imaging unit relative to each other;

a pattern region detecting step of detecting a period and positional information in which a substantially identical image appears in an imaged image and detecting the pattern region corresponding to one period;

an evaluation region setting step of detecting positions in which the metallic patterns are formed on the dividing lines and of detecting a position in which no metallic pattern is formed on the planned dividing lines and setting the position with no metallic pattern as an evaluation region for evaluating quality of a processed groove;

an evaluation region deploying step of recording a position of the evaluation region in the pattern region and deploying the evaluation region at similar positions in different pattern regions;

a processing step of processing the wafer; and

a processed groove evaluating step of imaging processed grooves by imaging the evaluation region in at least two or more of the pattern regions, and determining the quality of the processed grooves.

2. The wafer processing method according to claim 1 , wherein:

the plurality of planned dividing lines are formed in a first direction and a second direction intersecting the first direction, and

the pattern region detecting step is performed in both the first direction and the second direction.

3. The wafer processing method according to claim 1 , wherein each of the plurality of metallic patterns comprises a test element group.

4. A method of processing a wafer having a plurality of identical pattern regions periodically formed on a top surface, the identical pattern regions each including a plurality of planned dividing lines intersecting each other and device regions demarcated by the plurality of planned dividing lines, the method comprising:

a holding step of holding an undersurface side of the wafer on a holding table;

an imaging step of imaging a plurality of positions on the top surface of the wafer while moving the holding table and an imaging unit relative to each other;

a pattern region detecting step of detecting a period and positional information in which a substantially identical image appears in an imaged image and detecting the pattern region corresponding to one period;

an evaluation region setting step of detecting a position in which no metallic pattern is formed on the planned dividing lines and setting the position as an evaluation region for evaluating quality of a processed groove;

an evaluation region deploying step of recording a position of the evaluation region in the pattern region and deploying the evaluation region at similar positions in different pattern regions;

a processing step of processing the wafer by irradiating the wafer with a laser beam; and

a processed groove evaluating step of imaging the evaluation region and emitted light generated by application of the laser beam during processing of the evaluation region and determining quality of processing conditions.