The Wet Etching Technology Of Phase Change Lithography Based On Al-Ni-Gd Metallic Glass

As the foundation of semiconductor processing technology, lithography holds an important part in the whole semiconductor manufacturing industry. Traditional lithography with organic optical resists and developer solution have been applied for decades. But demands grow as technology develops, the traditional way is approaching to a physical limit and no longer fulfills the need. Many new thoughts were presented these years, and among them all Phase-Change Lithography was considered the most potential one.Phase-Change Lithography employs inorganic phase-change materials over the organic ones. One of the differences between them is that phase-change materials have various formation and can be transformed from amorphous to crystalline under heat,which creates a variation in etching rate when they are both in the same etching solution.Challogenide compounds are most researched phase-change materials nowadays. In this thesis, metallic glass material Al Ni Gd is chose to be the new phase-change material,and studies of the wet etching methods were based on it.Single-layer and multi-layer AlNiGd film samples were prepared by the Magnetron Sputtering System firstly. After researches and experiments for the proper etching solution,an acid mixture and HF solution came to hand. For the best result the mixed solution was determined to be the combination of 2%nitric acid, 5% glacial acetic acid, 80%phosphoric acid, and 13% H2 O.The experimental methods of using the two solution to each etch one type of AlNiGd film samples were studied and optimized. Then the etching of the samples were tested both before and after annealing. Based on the results, in the same testing solution single-layer films etches 7 times speedier before annealing than after. With multi-layer films the speed difference even reached 46 times high. We call the difference the selective etching ratio.With the experiment methods demonstrated above and the data collected, the test had been moved to the final stage. Samples were lithographed with the knowledge of the selective etching ratio, and then etched in the same solution. At length expected patterns were obtained.