Silicon Wafer Manufacturing e-tour

How much do you know about silicon wafer manufacturing? Silicon wafers are the starting materials of most semiconductor devices. Just imagine a day without electronics. We will have no comfort in cars, no cellular phones, no PDA, no PSP, no game boy or even personal computers. Semiconductor chips have brought revolutionary changes to our lifestyle and are the key drivers and supporters of multimedia society.

Bear in mind that silicon wafer manufacturing is different from wafer fabrication. Raw silicon wafer manufacturing is to process silicon ingot into thin slice of wafer in specific diameter. These wafers will be used as raw material in wafer fabrication, which the manufacturer will process the wafer become up to hundreds of dies, depends on the wafer size. These dies will be process into integrated circuit by IC manufacturer.


I worked with silicon wafer manufacturer previously, and would like to share the basic knowledge on this industry, which I think somebody may be interested on it. Just treat it as kind of e-visit to wafer manufacturing site.

Wafer manufacturing process is started with:

 

Process 1: charging the ultra pure poly-crystalline silicon nuggets into a quartz crucible, and heating it up to around 1400°C. The output is silicon ingot.

Process 2: Slicing, the single crystal ingot cut into very thin wafers using a wire saw, or and inner diameter saw.

Process 3: Lapping, stain layer caused by slicing is removed from wafer surface, and thickness variation of wafers is improved.


Process 4: Etching, relieves mechanical strain and contamination in chemical solution. This process is also to improve surface flatness of wafer.


Process 5: Heat treatment, kills oxygen donors to stabilize resistivities.


Process 6: Polishing, makes mirror surfaces free from damages by mechano-chemical reactions.


Process 7: Cleaning, removes particles, heavy metals and other impurities.


Process 8: Inspections, ensures wafers manufactured are compliances to particle allowances, cosmetic specifications, like flatness, warp, dimple, pit, contamination, etc.


Process 9: Epitaxial grow, means the grow of silicon crystal firm upon a silicon crystal substrate. In an epitaxial reactor, epitaxial layer grows in a Si-H-Cl gas atmosphere with a dopant gas.


Process 10: Argon annealing at high temperature to annihilate crystalline defects near surface.


Process 11: Particle Count, if particle qty > specs, wafers required to go back to cleaning process. This is very important to prevent high reject rate in wafer manufacturing.



Process 12: Sampling check on wafer surface flatness as outgoing quality control.

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4 Responses to “Silicon Wafer Manufacturing e-tour”

  1. Elaine Says:

    This is interesting, one question, you have any idea in which process of the semiconductor manufacturing could possibly caused die crack? Let’s rule out the final packaging process.

  2. Celine Says:

    Hmm… I haven’t go through any rejects regarding die crack. We are producing raw silicon wafer, which emphasize in silicon wafer flatness, surface finishing & wafer cleanliness. Most probably for those working in semiconductor fabrication will have more appropriate answer.

  3. JOM thailand Says:

    Dear sir

    Nice to meet you ,i’m jom from thailand ,so my job concern about this ot this one ,but only test wafer -not wafer fabrication.
    Do you mind if i have some question concern about wafer fab for you?
    because i want re-locate for work job in this field at Singapore and malaysia .,so in thailand so far for raise this plants.
    Thank you so much for this blog and hopefully for visit this blog again.

    Best Regards
    JOM
    anupop.patsara@gmail.com

  4. Rusty Russell Says:

    I cannot see the pictures on this page, could you email the paper to me when you have 5 minutes.

    Thanks Rusty

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