The Apple iPhone SE is a 6s in a 5s body, but Chipworks dug into the internals and it turns out the story is more complicated than that. It straddles multiple generations - from the iPhone 5 selfie camera to the iPhone 6s chipset, a whopping four generations. The Apple A9 chipset is brand new and the SK Hynix-made LPDDR4 2GB memory matches the 6s as well. The NFC, audio chips and motion sensor are from that generation as well. The storage appears to be from the 6s as well, but an earlier 19nm chip instead of the 15nm being shipped now. The Qualcomm modem from the earlier iPhone 6 model...
Source: http://www.gsmarena.com/iphone_se_teardown_shows_hardware_ranging_from_iphone_5_to_6s-news-17552.php