Methods of forming resist pattern, forming electrode pattern, and manufacturing surface acoustic wave device

The method of forming an electrode pattern comprising the steps of:

• forming a resist pattern, the resist pattern being formed by:
• providing a substrate with a material having a refractive index n1;
• providing an antireflection film on a rear surface of the substrate comprising a semiconductor having a band gap energy of 3.4 eV or less and having a refractive index n2, wherein the reflectance expressed by (n1−n2)2/(n1+n2)2 is 0.15 or less;
• coating the substrate with a photoresist;
• radiating ultraviolet light on the photoresist through a photomask so that at least a portion of the photoresist becomes partly soluble in a developer;
• and
• soaking the substrate in the developer to remove the soluble photoresist thereby providing a partially exposed surface of the substrate and the resist pattern;
• further comprising
• providing a metal film on the partially exposed surface of the substrate and on the resist pattern;
• and
• removing the resist pattern together with the metal film formed on the resist pattern.

A method of manufacturing a surface acoustic wave device, comprising forming a resist pattern, the resist pattern being formed by:

• providing a substrate with a material having a refractive index n1;
• providing an antireflection film on a rear surface of the substrate comprising a semiconductor having a band gap energy of 3.4 eV or less and having a refractive index n2, wherein the reflectance expressed by (n1−n2)2/(n1+n2)2 is 0.15 or less;
• coating the substrate with a photoresist;
• radiating ultraviolet light on the photoresist through a photomask so that at least a portion of the photoresist becomes partly soluble in a developer;
• and
• soaking the substrate in the developer to remove the soluble photoresist.

A method of manufacturing a surface acoustic wave device, comprising forming an electrode pattern, the electrode pattern formed by forming a resist pattern by:

• providing a substrate with a material having a refractive index n1;
• providing an antireflection film on a rear surface of the substrate comprising a semiconductor having a band gap energy of 3.4 eV or less and having a refractive index n2, wherein the reflectance expressed by (n1−n2)2/(n1+n2)2 is 0.15 or less;
• coating the substrate with a photoresist;
• radiating ultraviolet light on the photoresist through a photomask so that at least a portion of the photoresist becomes partly soluble in a developer;
• and
• soaking the substrate in the developer to remove the soluble photoresist thereby providing a partially exposed surface of the substrate and the resist pattern;
• and further comprising:
• providing a metal film on the partially exposed surface of the substrate and on the resist pattern;
• and
• removing the resist pattern together with the metal film formed thereon.