| 摘要 |
PURPOSE:To prevent an unnecessary substance to be possibly precipitated on a silicon nitride film from being generated by forming a silicate glass layer which contains an impurity on the film, implanting the impurity with the film as a mask, and removing by etching the silicate glass layer with a mixture solution of fluoric acid and hydrogen peroxide. CONSTITUTION:A hole 3 is selectively formed in a silicon nitride film 2 on a semiconductor substrate 1, a silicate glass layer 4 which contains an impurity is formed on the film 2 over the hole 3. Then, with the film 2 as a mask an impurity is selectively implanted by heat treating, and the layer 4 is then removed by etching with mixture solution of fluoric acid and hydrogen peroxide. In this manner, for example, a trench capacitor of DRAM is manufactured. Thus, the silicate glass which contains the impurity can be removed easily without increasing the number of conventional steps or the influence to a locos layer while preventing an unnecessary substance to be possibly precipitated heretofore from being generated on the silicon nitride film. |
