| 摘要 |
PURPOSE: A tilt measuring device of a wafer surface is provided to measure a surface gradient of a semiconductor chip precisely, and to reduce an exposure failure by preventing irradiation to a planar semiconductor chip and by irradiating rays to uneven semiconductor chips. CONSTITUTION: A wafer surface tilt measuring apparatus comprises a light emitting unit(100) generating first measuring light and second reference light; a light irradiation unit(102) receiving at least five first rays from the light emitting unit, and irradiating the light to an exposed range of a wafer surface(108); a light receiving unit(103) receiving the first light reflected in the exposed range and the second rays more than 5 from the light emitting unit; a light channel unit(104) superposing first and second light, and measuring the tilt of exposed range by comparing the depth of a focus in the light overlap channel range; and control units(105a,105b) mounting optical fibers(101a,101b) between the light emitting unit, the light irradiation unit and the light receiving unit, and varying the channel range by shutting off or opening the optical passage of the optical fiber. The tilt measuring apparatus of the wafer surface moves the channel range by adjusting first and second light with the control unit, and prevents measurement errors by the surface tilt difference between the flat semiconductor chip and the uneven semiconductor chip.
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