Method for forming finely-structured parts, finely-structured parts formed thereby, and product using such finely-structured part

A matrix for molding a micro-lens array, the matrix comprising:

• a glass substrate having an array of hemisphere-like recesses formed therein,
• wherein said glass substrate contains at least one etching control component at a concentration which causes an elution of said etching control component from said glass substrate when being subjected to an isotropic etching process using an etching solution for the formation of said hemisphere-like recesses in said glass substrate,
• wherein said isotropic etching process comprises:
• applying a mask having an array of openings to said glass substrate;
• and
• etching said glass substrate with said etching solution so that said array of hemisphere-like recesses is formed so as to correspond to said array of openings, the etching of said glass substrate being allowed to continue until the etching is stopped when the etching control component eluted out said glass substrate in the etching solution accumulates on inner surfaces of said hemisphere-like recesses so that the inner surfaces of said hemisphere-like recesses are prevented from contacting a fresh part of the etching solution.