Steppings are organized by letter (a distinct version) and divided by number. If you're familiar with software updates for games or GPU drivers, C0 means version 3.0.
A stepping of C0 implies a somewhat longer development process than usual. For comparison, Ryzen 7000 Raphael chips use the B2 stepping, Ryzen 5000 Vermeer CPUs initially used the B0 stepping but later moved to B2, and Intel's Raptor Lake processors are all on B0. Alder Lake CPUs had a stepping of C0, much like Meteor Lake, and there are parallels between the two chips.
You might need to check some of the data on the CPU’s “stepping” and the revision of the silicon. Apart from being in a longer development process, a letter change could also signify a change to both the base layer mask revision and metal layers, whereas a change in the number could indicate a change in the metal layer mask revision only, in Intel’s terminology.
But for consumers and end-users the stepping/revision number is not THAT much of an issue while purchasing new silicon.
But in any case,
not all Ryzen 7000 Raphael chips use the B2 stepping. Check the database and spec sheets again. Also, the statement,
“Intel's Raptor Lake/RPL processors are all on B0” is also not accurate.
Some of the SKUs in the final RPL lineup sport the previous Alder Lake C0 silicon. Few processors also use the H0 die.
The same is true for Alder Lake-S/ADL as well. Alder Lake CPUs didn’t just have a stepping of C0 either. For example, the final Retail version of the Intel Alder Lake-S 6-core i5-12400 CPU uses the C0 silicon, even though there is one more variants in the market, sporting both the H0 silicon die.
There are more SKUs as well.
Basically for the ADL lineup, two silicon stepping variations were used, C0 and H0, which showcased both the 8+8 full core implementation (C0), with the slimmer variation lacking the smaller Efficient cores (H0 die).
Btw, the 10-core Alder Lake-K SKU sports the C0 silicon stepping (i5-12600K), and one using a lesser 6-core non-K SKU is based on the H0 silicon stepping (i5-12600).