Ruling Regarding Semen
1-4-2003 | IslamWeb
Question:
What is the rule of semen? And how should we clean it if it falls on a carpet?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
The semen is pure according to the preponderant opinion of the Muslim scholars. The evidence is the Hadeeth reported by Muslim that a person stayed in the house of Aa’ishah 
and in the morning he began to wash his garment. Aa’ishah said: “In case you saw it (i.e. drop of semen), it would have served the purpose (of purifying the garment) if you had simply washed that spot; and in case you did not see it, it would have been enough to sprinkle water around it, for when I saw that on the garment of the Prophet , I simply scraped it off and he offered the prayer while putting that on.”
So, if the semen was impure chafing it would not have been sufficient, it would have been obligatory to purify it with water like the blood, the urine, and the pre-seminal charges and secretions.
In fact, scrubbing sperm is not obligatory as it is not impure. So, when it falls on the carpet it does not render it impure. But if some urine or some sexual discharges (not sperm) fall on the carpet, it should be removed and cleaned thoroughly with water. It takes the rule of the soil and is cleaned in the same way.
Abu Hurayrah 
narrated: “A Bedouin urinated in the mosque, and the people rushed to beat him. The Prophet ordered them to leave him and pour a bucket or a tumbler (full) of water over the place where he has passed urine. The Prophet then said, “You have been sent to make things easy (for the people) and you have not been sent to make things difficult for them.”
In principle, the floor of the bathroom is pure unless some impurities fall on it. So, unless one is certain that some impurities have fallen on the floor of the bathroom, he should consider the bathroom floor pure.
As long as you cleaned the bathroom and then walked on the carpet, then the carpet did not become impure unless you are certain to have walked on the very impurities. Then, only the place of the impurity must be purified.
Allah knows best.