Liquid chemical for forming water repellent protecting film, and process for cleaning wafers using the same
A liquid chemical for forming a water repellent protecting film on a wafer having at its surface an uneven pattern and containing at least one kind of element selected from the group consisting of titanium, tungsten, aluminum, copper, tin, tantalum and ruthenium at surfaces of recessed portions of the uneven pattern, the water repellent protecting film being formed at least on the surfaces of the recessed portions. The liquid chemical is characterized by including: a water repellent protecting film forming agent; and water, and characterized in that the water repellent protecting film forming agent is at least one selected from compounds represented by the following general formula [1] and salt compounds thereof and that the concentration of the water relative to the total quantity of a solvent contained in the liquid chemical is not smaller than 50 mass %.
1. A liquid chemical for forming a water repellent protecting film,
the liquid chemical for forming a water repellent protecting film being for forming a water repellent protecting film on a wafer having at its surface an uneven pattern and containing at least one kind of element selected from the group consisting of titanium, tungsten, aluminum, copper, tin, tantalum and ruthenium at surfaces of recessed portions of the uneven pattern, the water repellent protecting film being formed at least on the surfaces of the recessed portions, the liquid chemical comprising:
a water repellent protecting film forming agent; and
water,
wherein the concentration of the water relative to the total quantity of a solvent contained in the liquid chemical is not smaller than 50 mass %, and
wherein the water repellent protecting film forming agent is C 6 F 13 C 2 H 4 P(O)(OH) 2 .
2. The liquid chemical for forming a water repellent protecting film, as claimed in claim 1 , wherein an upper limit of the concentration of the water repellent protecting film forming agent relative to the total quantity of the liquid chemical is 1 mass %.
3. The liquid chemical for forming a water repellent protecting film, as claimed in claim 1 , wherein the concentration of the water repellent protecting film forming agent relative to the total quantity of the liquid chemical is 0.001 to 1 mass %.
4. The liquid chemical for forming a water repellent protecting film, as claimed in claim 1 , wherein the concentration of the water repellent protecting film forming agent relative to the total quantity of the liquid chemical is 0.0005 to 1 mass %.
5. The liquid chemical for forming a water repellent protecting film, as claimed in claim 1 , wherein the concentration of the water repellent protecting film forming agent relative to the total quantity of the liquid chemical is 0.0005 to 0.8 mass %.
6. The liquid chemical for forming a water repellent protecting film, as claimed in claim 1 , wherein the solvent is water or a liquid mixture containing water and at least one selected from the group consisting of esters, ethers, ketones, and polyalcohols having no hydroxyl group.