### 4.1.4 Summary to: 4.1 Input to Si Processing in an Industrial Environment

| Semiconductor technology happens in factories. They need special materials, "reticles" (= structures), "know-how" and huge amoundt of money (= capital) as major inputs |  |
|  | It's always about money! Only mass production will recover large investments. |
|  | The materials side always contains semiconductor substrates ("wafers") and often very dangerous special "raw" materials. |
|  | A number tells it all: 500 - 1.000 wafers /day are processed in a large Si "wafer fab" |
| Three big steps to Si wafers |  |
Sand (SiO2) Metallurgical Si Poly-Si | Þ Þ Þ | Metallurgical Si clean (doped) poly-Si. Single crystal / wafer
--- | --- | ---
|  | Si single crystal growth is done by "Czochralski process" (CZ). |
|  | Dislocation-free crystals are possible but "bulk microdefects" and impurities cannot be totally avoided. |
|  | Nearly perfect 300 mm wafers are standard. |
Exercise 4.1-1
All Questions to 4.1

© H. Föll (Semiconductor Technology - Script)