linking a the_post_thumbnail() result

I would think this would be easy, but I am having issues finding the right solution….

My code is

<?php the_post_thumbnail(array(200,150)); ?>

However, it doesn’t make the thumbnail clickable. I want to be able to click the thumbnail and have it take me to the attachments.php template to show the bigger version.

I tried

“><?php the_post_thumbnail(array(200,150)); ?>

and

“><?php the_post_thumbnail(array(200,150)); ?>

and still not yielding the results I am looking for. Even changed the “Link To” field in the admin side of the thumbnail and nothing.

Any help?