Devices such as next-gen iPhones, Macs and iPad Pros are believed to be powered by processors supplied by the Taiwan Semiconductor Manufacturing Company (TSMC) as it has mastered the production of the bleeding-edge 2 nanometer production process. Now, the firm is said to be even closer to its target of producing this kind of silicon on schedule than expected.
Production yield is the percentage of chips on a wafer that can pass QC. Any semiconductor process will result in flaws present in the chips. Some of the flaws are minor and the chips can be downbinned and still used, but others will result in scrap. Yield is an important thing to track because it has major impacts on both the cost of chips produced on a process node, and the total output volume. Yield tends to improve over time as the process engineers tweak recipes and find sources of contamination/flaws. So 60% on a brand new process is pretty good.