Wafer manufacturing process flow and processing procedures

1. Surface cleaning: the wafer is cleaned to remove surface impurities and contaminants.

2. Initial oxidation: A silicon oxide layer is formed on the wafer surface as a basis for subsequent processing.

3. CVD deposition: using chemical vapor deposition method to deposit a layer of silicon nitride (Si3N4) on the wafer, used to isolate and protect circuit components.

4. Apply photoresist: Photoresist is applied to the wafer and steps such as pre-baking,wafer tester exposure, and development are performed to form the desired pattern.

5. Remove Silicon Nitride: Use dry oxidation to remove the silicon nitride layer, exposing the underlying silicon material.

6. Ion Fabrication: Boron ions are injected into the wafer through ion implantation techniques to form P-traps for use in fabricating P-type transistors.

7. Annealing: The wafer is annealed in a high-temperature furnace to improve the performance of the transistor.

8. Photoresist Removal: The photoresist is removed in preparation for the next step in the process.

9. Hot Phosphoric Acid Silicon Nitride Removal: Remove the silicon nitride layer using hot phosphoric acid, doped with phosphorus ions, to form an N-type trap for making N-type transistors.

10. Annealing process: Annealing process is performed again to improve the performance of the transistor.

11. Removal of Gate Isolation Layer: HF solution is utilized to remove the SiO2 layer from the gate isolation layer and re-generate a better SiO2 film as the gate oxide layer.

12. LPCVD deposition of polycrystalline silicon layer: the use of low-pressure chemical vapor deposition method on the wafer to deposit a layer of polycrystalline silicon layer, used to make the gate structure.

13. Apply photoresist and etching: After applying photoresist, the silicon nitride layer on the lower gate isolation layer is retained by photolithography and ion etching techniques.

14. wet oxidation and growth of SiO2 layer: the use of wet oxidation growth of unprotected SiO2 layer of silicon nitride,wafer probe testing the formation of the isolation zone between the PN.

15. Hot Phosphoric Acid Removal of Silicon Nitride and HF Removal of SiO2 Layer: Use hot phosphoric acid to remove the silicon nitride layer and then use HF solution to remove the SiO2 layer at the location of the gate isolation layer and re-generate a better quality SiO2 film as the gate oxide layer.

16. LPCVD Deposition of Polysilicon Layer and Photoresist Coating: A polysilicon layer is deposited using Low Pressure Chemical Vapor Deposition (LPCVD), and then a photoresist is coated for photolithography and plasma etching techniques to form the gate structure and the source-drain electrode.

17. Surface coated photoresist and ion implantation: After removing photoresist in the P-well region, arsenic ions are injected to form the source-drain of NMOS;vibration isolation table boron ions are injected in the N-well region to form the source-drain of PMOS.

18. PECVD Deposition of Undoped Oxide Layer and Annealing: A layer of undoped oxide is deposited using plasma-enhanced chemical vapor deposition (PECVD) to protect the components and annealing is performed.

19. Deposition of Boron-Phosphorus Doped Oxide Layer: Deposition of a boron-phosphorus doped oxide layer on a wafer.

20. Sputtering of the first metal layer: a thin metal film is deposited on the wafer using sputtering as a material for connecting wires and electrodes.

21. Photolithography and Ion Etching: Use photolithography and ion etching techniques to define VIA vias, PAD locations, etc.

22. Deposition of second layer of metal and etching of connecting structures: Deposition of a second layer of metal on the wafer and formation of connecting structures by etching techniques.

23. PECVD Oxide and Silicon Nitride Protective Layers: Deposition of an oxide layer and a silicon nitride protective layer using PECVD.

24. Annealing: A final annealing process is performed to ensure the integrity of the entire chip and connectivity of the wires.