Vector2 Error when Declaring new Vector3

Hello,

I'm currently working on a project that uses the ScreenToWorldPoint function to develop a touch control system.

Here's the line in question:

 var touchPosition : Vector3 = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, 0, touch.position.z));

I want to use "Camera.main.ScreenToWorldPoint" to create a new Vector3. However, my console returns the following error when I compile the code.

Error BCE0019: 'z' is not a member of 'UnityEngine.Vector2'. Did you mean 'x'? (BCE0019).

I think the issue is that it believes I want a 2d vector when in reality I want to create a 3d vector.

Here's the complete code for reference.

 function Update () {
   var object : GameObject;
       for(var touch : Touch in Input.touches){
       if(Input.touchCount > 0) {
           // Check for Touch on Screen.
 
         if(touch.phase == TouchPhase.Began || touch.phase == TouchPhase.Moved) {
             var touchPosition : Vector3 = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, 0, touch.position.z));
             // Create Vector from Touch Position, and "ScreenToWorldPoint" Function.
             transform.position = Vector3.Lerp(transform.position, touchPosition, Time.deltaTime);
             // Smoothly Translate GameObject according to Last Frame, Touch Position, and Time.
             transform.LookAt(touchPosition, Vector3.up);
             // Orient GameObject according to Touch Posiition.
             }
         }
     }
 }

I'm sure there's something right in front of me that I'm missing but I've been fighting with this for a little too long so I'm turning to the community!

Thanks for any help!