How to tile with out gaps ?

In my game I have to create a tiled wall. I am scaling the tiles based on screen size and place them one after the other until it fills the wall from top to bottom using following code. The origin of the tile is at upper left corner.

currentPos = screenHeight;
		
while (currentPos > 0)
{
	Instantiate(tile,currentPos,Quaternion.identity);
	currentPos -= tileHeight;
}

The code works correctly but I can see a small gap between 2 tiles. I assume this is because when I re-size the tile, it is not re-sized to whole number but with fractions.

Can anyone provide some solution to fix this?

can anyone suggest a solution for this?