Surface inspecting apparatus and method

A surface inspection apparatus comprising:

• a tight source section for emitting a first luminous flux and a second luminous flux;
• a first irradiation optical system in which the first luminous flux is irradiated on the surface of an inspected object at a first irradiation angle;
• a second irradiation optical system in which the second luminous flux is irradiated on the surface of an inspected object at a second irradiation angle different from the first irradiation angle;
• a light receiving optical system for receiving scattered light of the first luminous flux irradiated by the first irradiation optical system and produced from an inspection object on the surface of an inspected object and scattered light of the second luminous flux irradiated by the second irradiation optical system and produced from an inspection object on the surface of an inspected object;
• a first light receiving section for converting the scattered light of the first luminous flux received by the light receiving optical system into a first light receiving signal;
• a second light receiving section for converting the scattered light of the second luminous flux received by the light receiving optical system into a second light receiving signal;
• a displacement section for relatively displacing an inspected object and an irradiation luminous flux of the irradiation optical system;
• and
• a discrimination section for discriminating the kind of an inspection object on an inspected object on the basis of the strength of the scattered light of the first and second light receiving signals, and the scattered range of the scattered light of the first and second light receiving signals,
• wherein the kind of the inspection object discriminated by the discrimination section is decided according to what kind the inspected object is, and
• wherein where an inspected object is a bare wafer, the discrimination section discriminates COP (crystal defect) as a first inspection object by a first discrimination process, discriminates COP (crystal defect) as a second inspection object by a second discrimination process, and discriminates a thin foreign matter as a third inspection object by a third discrimination process.

A surface inspection apparatus comprising:

• a light source section for emitting a first luminous flux and a second luminous flux;
• a first irradiation optical system in which the first luminous flux is irradiated on the surface of an inspected object at a first irradiation angle;
• a second irradiation optical system in which the second luminous flux is irradiated on the surface of an inspected object at a second irradiation angle different from the first irradiation angle;
• a light receiving optical system for receiving scattered light of the first luminous flux irradiated by the first irradiation optical system and produced from an inspection object on the surface of an inspected object and scattered light of the second luminous flux irradiated by the second irradiation optical system and produced from an inspection object on the surface of an inspected object;
• a first light receiving section for converting the scattered light of the first luminous flux received by the light receiving optical system into a first light receiving signal;
• a second light receiving section for converting the scattered light of the second luminous flux received by the light receiving optical system into a second light receiving signal;
• a displacement section for relatively displacing an inspected object and an irradiation luminous flux of the irradiation optical system;
• and
• a discrimination section for discriminating the kind of an inspection object on an inspected object on the basis of the strength of the scattered light of the first and second light receiving signals, and the scattered range of the scattered light of the first and second light receiving signals,
• wherein the kind of the inspection object discriminated by the discrimination section is decided according to what kind the inspected object is, and
• wherein where an inspected object is a semiconductor wafer after CMP (chemical mechanical process) process of a wafer with a membrane, the discrimination section discriminates COP (crystal defect) as a first foreign matter by a first discrimination process, discriminates a micro-scratch as a second foreign matter by a second discrimination process, and discriminates a micro-scratch as a third foreign matter by a third discrimination process.

A surface inspection method, in a method for discriminating a foreign matter in a state for relatively displacing an inspected object and an irradiation luminous flux of an irradiation optical system by a displacement section, comprising:

• a step of irradiating a first luminous flux on the surface of an inspected object at a first irradiation angle, and irradiating a second luminous flux on the surface of an inspected object at a second irradiation angle different from the first irradiation angle;
• a step of receiving scattered light of the first luminous flux and the second luminous flux irradiated by the irradiation optical system and produced from an inspection object on the surface of an inspected object by the first light receiving section and the second light receiving section;
• a step of converting the scattered light of the first luminous flux received by the first light receiving section into a first light receiving signal, and converting the scattered light of the second luminous flux received by the second light receiving section into a second light receiving signal;
• and
• a step of discriminating the kind of an inspection object on an inspected object on the basis of the strength of the scattered light of the first and second light receiving signals, and the scattered range of the scattered light of the first and second light receiving signals.

A surface inspection method comprising:

• a step of emitting a first luminous flux and a second luminous flux;
• a step of irradiating the first luminous flux on the surface of an inspected object at a first irradiation angle;
• a step of irradiating the second luminous flux on the surface of an inspected object at a second irradiation angle different from the first irradiation angle;
• a step of receiving scattered light of the first luminous flux produced from an inspection object on the surface of an inspected object and scattered light of the second luminous flux produced from an inspection object on the surface of an inspected object;
• a step of converting the scattered light of the first luminous flux into a first light receiving signal;
• a step of converting the scattered light of the second luminous flux into a second light receiving signal;
• a step of relatively displacing an inspected object and an irradiation luminous flux;
• and
• a step of discriminating the kind of an inspection object on an inspected object on the basis of the strength of the scattered light of the first and second light receiving signals, and the scattered range of the scattered light of the first and second light receiving signals.

A surface inspection apparatus comprising:

• a means for emitting a first luminous flux and a second luminous flux;
• a means for irradiating the first luminous flux on the surface of an inspected object at a first irradiation angle;
• a means for irradiating the second luminous flux on the surface of an inspected object at a second irradiation angle different from the first irradiation angle;
• a means for receiving scattered light of the first luminous produced from an inspection object on the surface of an inspected object and scattered light of the second luminous flux produced from an inspection object on the surface of an inspected object;
• a means for converting the scattered light of the first luminous flux received by the light receiving means into a first light receiving signal;
• a means for converting the scattered light of the second luminous flux into received by the light receiving means a second light receiving signal;
• a means for relatively displacing an inspected object and an irradiation luminous flux;
• and
• a means for discriminating the kind of an inspection object on an inspected object on the basis of the strength of the scattered light of the first and second light receiving signals, and the scattered range of the scattered light of the first and second light receiving signals.