Method for producing radiation-sensitive resin composition and pattern forming method

A method for producing a radiation-sensitive resin composition, the method being for producing a radiation-sensitive resin composition using a stirring device provided with a stirring tank and a stirrer, comprising:

• a mixing step of charging a resin, an acid generator, and a solvent into the stirring tank to obtain a mixture including the resin, the acid generator, and the solvent;
• and
• a stirring step of stirring the mixture accommodated in the stirring tank, using the stirrer,
• wherein a mass ratio c of a content of the acid generator to a total mass of the mixture is 0.003 to 0.025 by mass,
• the stirrer is provided with a rotatable stirring shaft, a plurality of support parts attached to the stirring shaft, and a plurality of stirring elements attached to each of end parts of the plurality of support parts,
• the stirring element consists of a tubular body having a first opening portion and a second opening portion facing each other,
• an opening area of the first opening portion is wider than an opening area of the second opening portion,
• the stirring element is arranged such that a direction from the second opening portion to the first opening portion coincides with a rotation direction of the stirring shaft,
• a central axis of the tubular body is inclined with respect to a plane orthogonal to the stirring shaft,
• the stirrer satisfies Expression (1),
• h=h1/h2≤−0.2×ln(c)+0.25 (1)
• in Expression (1), h represents a ratio of an average value of depths from the plurality of stirring elements (h1) from a bottom of the stirring tank relative to a depth of a liquid level from the bottom of the stirring tank (h2) accommodated in the stirring tank, and ln(c) represents a natural logarithm of the ratio c,
• a rotation speed of the stirring shaft is changed by repeating a period of rotating the stirring shaft and a period of stopping the rotation of the stirring shaft, or by repeating a plurality of periods having different rotation speeds including at least a period A having a relatively high rotation speed and a period B having a relatively slow rotation speed in the stirring step, and
• the stirrer satisfies Expression (3),
• 1/16≤d1/d2≤⅜ (3)
• in Expression (3), d1 represents a distance between a point C1 located at a center of the plurality of stirring elements and a point C2 located at a center of an inner peripheral surface of the stirring tank in a case where the stirring device is observed from a vertical direction, and
• d2 represents an inner diameter of the stirring tank in a cross-section of the stirring tank in a horizontal direction.