Growth of $\phi$-order solutions of linear differential equations with meromorphic coefficients on the complex plane

In this paper, we study the growth of solutions of higher order linear differential equations with meromorphic coefficients of $\phi$-order on the complex plane. By considering the concepts of $\phi$-order and $\phi$-type, we will extend and improve many previous results due to Chyzhykov-Semochko, Belaïdi, Cao-Xu-Chen, Kinnunen.