Like the governor, her goal is to get the state’s minimum wage to $15, more than double the federal minimum wage of $7.25 and equal to the level it will reach in California in 2022 and in Massachusetts the following year. As of Tuesday evening, specifics were still being worked out, and debate among lawmakers could further change any proposal. Up for discussion is how many years it should take to boost the wage to $15, whether employers should continue being allowed to pay some teenage workers less and how to structure tax credits to help small businesses offset rising payroll costs.