A memory device includes a plurality of memory cells arranged in a plurality of rows and a plurality of strings. A method of programming the memory device includes programming a first row of the memory cells. The method also includes, after programing the first row of the memory cells, programming a second row of the memory cells. The second row is adjacent to the first row in a first string direction. The method further includes, after programming the second row of the memory cells, programming a third row of the memory cells. The third row is two rows apart from the second row in a second string direction opposite to the first string direction.