| 摘要 |
PURPOSE:To minimize the damage of a crystal and facilitate an accurate measurement of a surface distribution of the growth thickness of the crystal by a method wherein a plurality of stepped regions are provided to evenly distributed position in a wafer for measurement and their areas are minimized. CONSTITUTION:In order to measure the growth thickness of a multi-layer epitaxial crystal for an InGaAsP/InP system semiconductor laser, an etching protection film, to which 12 holes are provided, is formed and, after a P-InGaAsP cap layer 4 is removed by a sulfuric acid system solution, P-InP cladding layer 3 is removed by a hydrochloric acid system solution and an InGaAsP undoped activated layer is exposed to form stepped parts. After the etching protection film is removed, the stepped parts are measured by a needle probe method and a layer thickneess distribution in a wafer surface of the P-InGaAsP cap layer plus the P-InP cladding layer is obtained. |
