Conversion of spermatid into spermatozoa is

Conversion of spermatid into spermatozoa is Spermiogenesis.
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules.
Spermatogenesis produces mature male gametes, commonly called sperm but more specifically known as spermatozoa, which can fertilize the counterpart female gamete, the oocyte, during conception to produce a single-celled individual known as a zygote.