Micron Technology Inc. and Western Digital Corp. are each exploring a potential deal for Kioxia Holdings Corp. that could value the Japanese semiconductor company at roughly $30 billion, as a global disorder for memory chips used in smartphones and other devices heats up.A deal for Kioxia, controlled by private-equity firm Bain Capital, isn’t guaranteed, and it isn’t clear how one might be assembled. Should a deal come together, it could be completed later this spring.The Tokyo-based company had been planning an initial public offering before shelving it in late September, citing the coronavirus pandemic and market volatility.An IPO later this year is still a possibility should the company fail to reach an agreement with one of the suitors.