Why is L1 cache faster than L2 cache?
No, they're not the same type of RAM, even though they're on the same chip that uses the same manufacturing process.

Of all the caches, the L1 cache needs to have the fastest possible access time (lowest latency), versus how much capacity it needs to have in order to provide an adequate "hit" rate. Therefore, it is built using larger transistors and wider metal tracks, trading off space and power for speed. The higher-level caches need to have higher capacities, but can afford to be slower, so they use smaller transistors that are packed more tightly.