Detector and detection system

A detector comprising:

• a substrate;
• and
• an insulating film formed over a main surface of the substrate,
• wherein the substrate includes
• a conversion element portion configured to convert an energy ray into a signal charge, and
• an insulator region disposed in a recess portion of the main surface,
• wherein the conversion element portion includes
• a first semiconductor region that is formed on the main surface and is of a first conductivity type in which charges of the same polarity as the signal charge are used as majority carriers,
• a second semiconductor region that is formed on the main surface and is of a second conductivity type different from the first conductivity type, and
• a third semiconductor region that is formed under the first semiconductor region and the second semiconductor region, is of the first conductivity type, and has an impurity concentration lower than an impurity concentration of the first semiconductor region, and
• wherein in a plan view with respect to the main surface, the insulator region is located between the first semiconductor region and the second semiconductor region in at least one direction.