Zaid is a liar, He borrowed some money from me. After sometime he denied and he started telling lying. When issue reached high I told him to take swear of Allah and He swear (false) that He (Zaid) did not take any money. Did i do any sin to force him take false swear of Allah?
Per Islam, either the person claiming someone took something from them gives evidence OR in the lack of that evidence... the other person against whom the claim is made takes an oath. This is established from the Sunnah.
Ibn Abbas reported Allah's Apostle (ﷺ) as saying: لو يعطى الناس بدعواهم لادعى ناس دماء رجال وأموالهم ولكن اليمين على المدعى عليه (If the people were given according to their claims, they would claim the lives of persons and their properties, but the oath must be taken by the defendant) - Muslim (1711).
If you didn't use threats/force against him, then you didn't do anything wrong. He chose his own actions.