Yes.
They are made by supermicro.
But they are really expensive and it might be better to build one out tiny.
The SYS-E200-8D supports up to 128GB with DDR4 ECC RDIMM and up to 64GB with DDR4 ECC UDIMM. Supermicro Superserver SYS-E200-8D Mini 1U Server. Manufacturer Supermicro. Compact Mini 1U Form Factor. Supermicro 1U Options.
www.ebay.com
How small are we looking at?
Like a NUC size? if that's the case you need to go industrial solution.
Can i ask why you need a Mini with ECC support?
Just increasing the size to a 1U rack would save you 70% of the cost.