Light detection device, film thickness measurement device, semiconductor process monitoring device, and noise detection method

A light detection device comprising:

• a light detector configured to detect measurement light;
• and
• circuitry configured to process data output from the light detector,
• wherein the light detector comprises:
• first detector including comprising a plurality of first pixel columns arranged along a first direction, wherein each of the plurality of first pixel columns comprises at least one pixel arranged along a second direction perpendicular to the first direction;
• and
• second detector comprising a plurality of second pixel columns arranged along the first direction, wherein each of the plurality of second pixel columns comprises at least one pixel arranged along the second direction, wherein the first detector and the second detector are arranged so as to be adjacent to each other in the second direction,
• wherein the light detector outputs a first signal and a second signal to the circuitry, wherein the first signal is one-dimensional data in the first direction of the measurement light detected by the first detector, wherein the second signal is one-dimensional data in the first direction of the measurement light detected by the second detector,
• wherein the light detector comprises a plurality of channels arranged along the first direction assuming that one channel is formed by the first pixel column and the second pixel column arranged in the second direction,
• wherein the circuitry sets a threshold respectively for each of the plurality of channels,
• wherein the circuitry identifies a target channel among the plurality of channels based on the threshold and a signal difference between the first signal and the second signal in each of the plurality of channels, wherein noise is included in the first signal or the second signal of the target channel,
• wherein the threshold is set based on a difference value, and the difference value includes;
• a first difference between a value of the first signal in a referring channel among the plurality of channels and a value of the first signal in a first proximity channel which is proximate to the referring channel;
• and
• a second difference between a value of the second signal in the referring channel and a value of the second signal in a second proximity channel which is proximate to the referring channel.