Method for fabricating a semiconductor device including a step for cleaning a semiconductor substrate

A method for fabricating a semiconductor device, comprising the steps of:

• cleaning a semiconductor substrate in a cleaning liquid essentially consisted of a mixture of an ammonia water having a composition of 29 percent by weight, a hydrogen peroxide aqueous solution having a composition of 31 percent by weight and a deionized water, said cleaning liquid containing the ammonia water and the hydrogen peroxide aqueous solution with respective volume parts such that the volume part of the ammonia water is set equal to or smaller than 30 parts with respect to the deionized water of 1000 parts, said volume part of the ammonia water being set equal to or smaller than the volume part of the hydrogen peroxide aqueous solution, said volume part of the hydrogen peroxide aqueous solution being set equal to or smaller than 100 parts with respect to the deionized water of 1000 parts, said volume part of the hydrogen peroxide aqueous solution being further set equal to or smaller than a boundary composition Y2 represented as
• Y.sub.2 =0.25X.sup.3 -2.75X.sup.2 +13.5X-10,
• where X represents the volume part of the ammonia water in 1000 parts of said deionized water;
• rinsing the semiconductor substrate that has been cleaned in the cleaning liquid;
• and
• drying the semiconductor substrate.