An object of the present invention is to provide a treatment liquid for manufacturing a semiconductor and a pattern forming method, in which the formation of particles including metal atoms can be reduced and an excellent pattern can be formed.
A treatment liquid for manufacturing a semiconductor according to an embodiment of the present invention includes: a quaternary ammonium compound represented by Formula (N); at least one additive selected from the group consisting of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and a chelating agent; and water. The treatment liquid for manufacturing a semiconductor includes one kind or two or more kinds of metal atoms selected from the group consisting of Na, K, Ca, Fe, Cu, Mg, Mn, Li, Al, Cr, Ni, and Zn, and a total mass of the metal atoms is 1 mass ppt to 1 mass ppm with respect to the sum of a total mass of the additive and the total mass of the metal atoms.