Randomly Initiate Cubes - Prevent Same Position

Hello,

I'm spawning a load of cubes in my scene, using RandomRange to give it a random location. However I don't want to spawn a cube in the same position as any previous cubes.

So what it currently does is spawn a cube a 0,0,0 and then it caches that position.

It is then passed to a function that checks through all the cached positions and looks for any repeats, if so - then it will change the position, and keep doing so until it finds a new position.

But right now, my cubes just keep jumping everywhere, not finding a location. Need a fresh pair of eyes to look at this for me :/

Thanks:

 function InitiateGame(){
 
     print("Initiating Game!");
 
 
     for(var i = 0; i < tileCount; i++){
 
         //spawn tile at a position of 0,0,0
         var tile = Instantiate(memoryTile, Vector3(0, 0, 0), transform.rotation);
         tile.transform.parent = spawnLocation.transform;
         //cache the location
         tileCache[i] = tile.transform.position;
 
         //check if random positions havnt overlapped
         RandomLocation(tile.transform);
 
         counter++;
 
         yield WaitForSeconds(1);
     }
 }
 
 
 
 function RandomLocation(tile : Transform){
 
     for(var i = 0; i <= counter; i++){
 
         while(tile.position == tileCache[i]){
 
             print("Tile is same position");

           //i think the jumping problem lies within here, as its caching the new location, so its still the same position!
             tile.position = RandomVector();
             tileCache[i] = tile.position;
 
             yield;
         }
     }
 }
 
 
 function RandomVector(){
 
     var posX = Mathf.Round(Random.Range(-0.4, 0.4) * 10) / 10;
     var posY = Mathf.Round(Random.Range(-0.7, 0.7) * 10) / 10;
 
     return Vector3(posX, posY, 0);
 }

I'm sure theres a better way to do this too ? Any ideas?