Which minimum sallary you are refering too the one who is applying for the visa or to pay to the maid?? if it is the sallary of maid then it goes from QAR 500 to QAR 1500 depends filipino maids are officially should be paid over QAR 100 but I know people still getting them around QAR 600-700. You will require a company letter from your employer as well as the wife's employer plus copies of your and your wife's RP plus copy of your kids RP and your original ID. I hope this answers your question.