Is there a fix for right side dead zone?

Assuming you've removed any screen protector, then about the only thing left would be to do a restore to wipe the phone back to factory settings. Once you've done that, you have eliminated all possible software issues and are left with a hardware problem.

In this case, the part responsible for handling the touch screen is the digitizer. It's a layer of glass bonded to the LCD display as one unit, so in order to replace a defective digitizer, you need to replace the screen.

Digitizers are very similar to LCDs in that they are connected to the motherboard using a flex cable that is bonded to the glass. Unfortunately, it's all too easy to disrupt those connections, and on the digitizer you end up with a malfunctioning touch screen; on the LCD you'll see lines or spots on the screen. Depending on the extent of the damage, you could have a partially working touchscreen, or nothing at all working.

Anyway, as I mentioned, the fix after all the software options have been exhausted is to replace the screen. iFixit has a guide showing you step by step how to replace the screen on your iPhone SE.

iPhone SE 2020 Screen Replacement - iFixit Repair Guide

If you follow the instructions you'll be fine; a couple of items from my experience that I would mention are first, to be sure the battery is disconnected first and reconnected last; you can damage the backlight circuit if you skip that step. Second, be sure to take extra care when swapping the home button over to the new screen; if you damage it you'll lose Touch ID permanently (well, unless you go to Apple and pay full price for a screen replacement).

You can support iFixit's repair efforts by purchasing the screen directly from them; it comes with a lifetime warranty and if you need tools for a minimum additional cost you can get the Fix Kit that includes all of the tools and adhesives needed to do the job right. If, however, you need to save money, you can find replacement parts on sites like Amazon, eBay and AliExpress for substantial savings.

Good luck and let us know how it all turns out!