How to prevent friction for character along vertical surfaces?

I have made a simple 2d character with movement using rigid-body physics, however when it tries to jump along side a wall, the friction causes it to stop half way up the wall, which is unrealistic and makes it difficult to jump in certain places. How can I prevent friction along vertical surfaces?

Here is my code:

 public var spawnPoint : Transform;
 public var deathPoint : Collider;
 public var horizontalSpeed : float = 5.0;
 public var verticalSpeed : float = 5.0;
 public var acceleration : float = 5.0;
 public var deceleration : float = 5.0;
 public var jumpStrength : float = 5.0;
 public var glideStrength : float = 2.0;
 public var stampStrength : float = 5.0;
 public var maxJumpSlope : float = 45.0;
 @HideInInspector
 public var horizontalVelocity : Vector2;
 @HideInInspector
 public var verticalVelocity : Vector2;
 @HideInInspector
 public var grounded : boolean = false;
 @HideInInspector
 public var xVelocity : float;
 
 //move player to spawn point
 transform.position = spawnPoint.position;
 
 function FixedUpdate () {
     //jump only if player is touching ground
     if (Input.GetAxis("Vertical") > 0) {
         if (grounded) {
             rigidbody.AddForce(Vector2(0,jumpStrength));
         }
         else {
             rigidbody.AddForce(Vector2(0,glideStrength));
         }
     }
     else if (Input.GetAxis("Vertical") < 0) {
         rigidbody.AddForce(Vector2(0,-stampStrength));
     }
     
     //maintain player vertical velocity at consistent max speed
     verticalVelocity = Vector2(0,rigidbody.velocity.y);
     if (verticalVelocity.magnitude > verticalSpeed) {    
         verticalVelocity.Normalize();
         verticalVelocity *= verticalSpeed;
         rigidbody.velocity.y = verticalVelocity.y;
     }
             
         
     //accelerate player from user input
     rigidbody.AddForce(Vector2(Input.GetAxis("Horizontal") * acceleration,0));
     //maintain player horizontal velocity at consistent max speed
     horizontalVelocity = Vector2(rigidbody.velocity.x, 0);
     if (horizontalVelocity.magnitude > horizontalSpeed) {    
         horizontalVelocity.Normalize();
         horizontalVelocity *= horizontalSpeed;
         rigidbody.velocity.x = horizontalVelocity.x;
     }
     //decelerate player if on ground
     if (grounded && Input.GetAxis("Horizontal") == 0) {
         rigidbody.velocity.x = Mathf.SmoothDamp(rigidbody.velocity.x,0,xVelocity,deceleration);
     }
     
 }
 
 function OnCollisionStay (collisionInfo : Collision) {
     for (var contact : ContactPoint in collisionInfo.contacts) {
         //grounded is true if the slope the player is standing on is below a set angle
         if (Vector3.Angle(Vector3.up, contact.normal) < maxJumpSlope) {
             grounded = true;
         }
         //respawn player if fallen from edge
         if (contact.otherCollider == deathPoint) {
             transform.position = spawnPoint.position; 
         }
     }
 }
 
 function OnCollisionExit () {
     grounded = false;
 }