How to VR off-screen rendering?

I tired to below... 1. set render texture to secoundary camera ( with both eye ). 2. set texture to plane. 3. rendering plane with main camera. After that, I checked left eye and right eye. Two planes are completely same.

I think that plane in left eye is rendered with result for left eye rendering in secondary camera.

For solving this, I want to get two textures (one is left eye other is right eye). How can I this? Please help.