Process for cleaning, drying and hydrophilizing a semiconductor wafer
View Patent ↗Semiconductor wafers are cleaned, dried, and hydrophilized the following steps in the order stated: a) treating the semiconductor wafer with a liquid aqueous solution containing hydrogen fluoride, the semiconductor wafer rotating about its center axis at least occasionally, and b) drying the semiconductor wafer by rotation of the semiconductor wafer about its center axis at a rotational speed of 1000 to 5000 revolutions per minute in an ozone-containing atmosphere, the liquid aqueous solution containing hydrogen fluoride flowing away from the semiconductor wafer on account of the centrifugal force generated by the rotation, and the surface of the semiconductor wafer being hydrophilized by ozone.
1. A process for cleaning, drying and hydrophilizing a semiconductor wafer, comprising the following steps in the order stated:
a) applying a liquid aqueous solution containing hydrogen fluoride onto the semiconductor wafer while the semiconductor wafer is caused to rotate about its center axis at least occasionally, so that the liquid aqueous solution containing hydrogen fluoride flows away outwards and forms a continuous liquid film on the semiconductor wafer, and
b) directly following step a), completely drying the semiconductor wafer by rotation of the semiconductor wafer about its center axis at a rotational speed of 1000 to 5000 revolutions per minute in an ozone-containing atmosphere having a concentration of ozone of 5 to 20 percent by weight, the liquid aqueous solution containing hydrogen fluoride flowing away from the semiconductor wafer on account of the centrifugal force generated by the rotation, and the surface of the semiconductor wafer being hydrophilized by ozone, wherein the semiconductor wafer is exposed to the ozone-containing atmosphere starting from a point in time at which the semiconductor wafer is still covered with the continuous liquid film, and continues until the semiconductor wafer is completely dry.
2. The process of claim 1 , wherein the rotational speed in step b) is 2000 to 3000 revolutions per minute.
3. The process of claim 1 , wherein the concentration of the hydrogen fluoride in the liquid aqueous solution in steps a) and b) is 0.01 to 2 percent by weight.
4. The process of claim 2 , wherein the concentration of the hydrogen fluoride in the liquid aqueous solution in steps a) and b) is 0.01 to 2 percent by weight.
5. The process of claim 3 , wherein the concentration of the hydrogen fluoride in the liquid aqueous solution which is situated on the surface of the semiconductor wafer after step a) is not changed before step b).
6. The process of claim 1 , wherein step a) is carried out under an ozone-containing atmosphere.
7. The process of claim 6 , wherein concentration of ozone in the atmosphere in step a) is 5 to 20 percent by weight.
8. The process of claim 1 , wherein the liquid aqueous solution contains ozone.
9. The process of claim 1 , wherein that the process is carried out by means of an individual-wafer cleaning device.
10. The process of claim 1 , wherein following step a), no rinsing of the wafer occurs.