| 摘要 |
PURPOSE:To reduce the leak current after etching without reducing the processing efficiency by a method wherein, when the surface of the P-N joint an Si substrate is etched, water solution containing HF is used in an inert gas atmosphere substantially containing no O2. CONSTITUTION:The best inert gas to reduce leak current is Ne followed by Ar and He. Besides the elements with numerous P-N joints such as SCR and the like are contained in a gas atmosphere mixed with two kinds of said gases and the solution mixed with acetic acid, phosphoric acid, nitric acid or iodine subject to the specified concentration and the compounding ratio in addition to HF is used for etching. Through the constitution, the etching may be performed without deteriorating the etching efficiency to reduce the leak current of the elements after etching. An example of the etching solution comprises 100 volume parts of HF water solution, 250 volume parts of nitric acid water solution, 80 volume parts of phosphoric acid and the like with respective concentration of 49wt%, 70wt% and 99wt%. |
