| 摘要 |
PURPOSE:To simplify a grooving stage and to reduce the time for grooving by combining a machining using a dicing saw or wire saw and isotropic etching by a chemical etching method to perform grooving to a glass substrate. CONSTITUTION:A substrate 1 having resist 2 is machined with a tentative groove 4 having a depth d1 along a pattern 3 by an adequate machining means such as a dicing saw or wire saw, etc. After the resist 2 is removed, the groove 4 is chemically etched at an ordinary temp. by using hydrofluoric acid by which the tentative groove is trimmed and a groove 7 for an optical waveguide is formed. A glass layer 8 having a refractive index n2 larger than the refractive index n1 of the glass substrte 1 is deposited on the grooved substrate 1 by using a technique of CVD method, etc. The part 8a on the substrate surface 1b of the deposited glass layer 8, a part of the part 8b in the groove 7 and the surface 1b of the substrate 1 are removed by polishing so that the remaining glass layer part 8b in the groove 7 remains. The polished surface 1c thereof is finished to a smooth surface having optically good surface accuracy. Another glass layer 9 having the refractive index approximately equal to the refractive index of the substrate 1 is then deposited and formed on the above-mentioned layer by CVD method and the remaining glass layer part 8b in the groove 7 is formed as the optical waveguide. |
