| 摘要 |
PURPOSE:To improve the luminous efficiency of a light emitting diode and the yield of products by measuring photo luminescence and electro luminescence of material to be inspected in a photon counting region, and estimating the luminous efficiency in a usual application region based on the above measured value. CONSTITUTION:Many luminous killer levels obstructing luminescence exist in material; minority carrier generated by excitation is firstly captured by said killer levels, so that the luminous intensity is proportional to about second order of the excitation amount. After the killer levels are filled with carrier, the luminous intensity transfers to a normal intense region. In this case, the relation, that the one of the lower transfer point has the higher luminous efficiency, exists. As a result, by performing the inspection in the weak excitation region in the vicinity of the above transfer points, the estimation of the luminous efficiency of material to be inspected is enabled. Thereby the short time excitation is available, so that the inspection time can be reduced. When the luminous distribution of substrate material is measured, the inspection is enabled by weak excitation divided into parts corresponding with each picture element, so that a wide area is easily inspected. |
