| 摘要 |
PURPOSE:To prevent the occurrence of cracks and to improve the resistance to humidity, by composing a passivation film of two layers, the lower layer of which is formed of a material containing an impurity in a high concentration and having an effect of relaxing stress and the upper layer of which is formed of a material containing an impurity in a low concentration or not containing it. CONSTITUTION:After the formation of a second wiring layer 13, a high- concentration PSG film 15 is first formed to be 2,000-5,000Angstrom thick as the lower layer. Subsequently, a low-concentration PSG film 16 is formed thereon as the upper layer. A thickness of this upper layer 16 is determined to be a value obtained by subtracting the thickness of the lower high-concentration PSG film 15 from a desired thickness for a passivation film. Preferably, a ratio of the thickness of the high-concentration PSG film 15 to the total thickness of the passivation film (the total of the upper and lower layers) is generally 30-50%. The PSG film 15 containing an impurity in a high concentration has a lower hardness and therefore has an effect of relaxing stress. The PSG film 16 containing an impurity in a low concentration has an excellent resistance to humidity. |
