1. Prepare the semiconductor material: - Grow a single-crystal semiconductor ingot, typically silicon[1][5][12] - Slice the ingot into thin wafers about 0.75 mm thick[12] - Polish the wafers to obtain a very flat, defect-free surface[5][12] 2. Introduce controlled impurities (doping) into the wafer: - Use diffusion[2][5] or ion implantation[2][5][8] to introduce dopants like boron or phosphorus into selected regions - Control the dopant concentration profile to form p-type and n-type regions[2][3] - Activate the dopants through thermal annealing[2][14] 3. Grow insulating layers: - Thermally oxidize the silicon surface to grow a silicon oxide (SiO2) layer[2][5][11] - Deposit other dielectric layers like silicon nitride using chemical vapor deposition (CVD)[6][10] 4. Define device patterns using lithography: - Coat the wafer with a light-sensitive photoresist[6] - Expose the resist through a patterned mask to define device features[5][6] - Develop the resist to form a patterned protective layer[6] 5. Etch exposed regions: - Use wet chemical etching or dry plasma etching to remove material from unprotected areas[2][6] - Create trenches, vias, or remove unwanted layers[1][4][7] 6. Deposit and pattern metal interconnects: - Deposit metal films like aluminum or copper using sputtering or evaporation[2][5] - Pattern the metal layer using lithography and etching to form interconnects[5][6] 7. Repeat steps 3-6 to build up multiple device layers[9][13] 8. Test and package the devices: - Probe individual devices on the wafer to test electrical properties[5] - Dice the wafer into individual chips[5] - Assemble the chips into protective packages and attach external leads[5][12] The key steps in semiconductor manufacturing include preparing defect-free crystalline wafers, introducing precise dopant profiles, growing insulating layers, patterning device features using lithography and etching, depositing and patterning metal interconnects, and finally packaging the devices. By carefully controlling each process step, complex integrated circuits containing billions of transistors can be reliably manufactured.