Adding CMP (Chemical-Mechanical Planarization) to chip production

Since the lens polisher will be added into the game in update 3, and likily only for lense production. I will suggest to rename the machine to "polisher" and add steps of CMP (Chemical-Mechanical Planarization) in each stage to make chip productin closer to reality.
I propose 2 directions of integrating such process into the game:
1. Directly add CMP after stage B and/or C in the original recipe, and uses acid and sand as polishing agent. This way the process will only require materials that are already the prerequisites of chip prodcution.
2. Add a "improved" version of chip production recipe chain further down the research tree. It will only be used on microchip machine II. For stage A, HF will be use instead of acid. Stage B would require copper, Silane (SiH4) and oxygen instead. And stage C would require lenses and plastic. After stage B and/or C, CMP is required, which requires diamond paste and HF. The yield of chips is doubled as a reward of using advanced procedure.

# What is CMP?
CMP stands for Chemical-Mechanical Planarization, which is a process of using chemicals and polishing agents to precisely flattened substrate surface. In wafer production, this step is performed at the end of each cycle. The process ensures a optimal surface for next stages, and is crucial for maintaining high yield.
# My idea on how to implement it
Keep the current production chain for accessibility and game progression sake. Instead, a new chain of wafer production recipe will be added, recipes as follow:
Here I will use stage A+, B+, C+, D+ to distinguish from original recipes.

1. In addition to construction parts IV, microchip machine II should also requires lens to build.
2. Production of stage A+ will require HF instead of acid.
3. Production of stage B+ will require copper, Silane (SiH4) + oxygen instead of plastic. (note 1. 4.)
4. SiH4 is produced in chemical plant using poly silicon and hydrogen. (note 2.)
5. Production of stage C+ will require nitrogen, aluminum and gold. (note 3.)
6. After stage C+, CMP is performed, resulting stage D+. The process requires diamonds (paste) and HF to planarize wafer. After planarization, stage D+ wafer can begin it's next cycle.
7. As an reward of using such advanced processing line, the yield is doubled (or tripled) per-wafer.