Types of Silicon and Common Growth Techniques

Overview:

Silicon chips are used in almost every electronic device around us. If you are aware of the concept of silicon chips, it is possible that you have searched about when was the silicon chip invented. But have you ever wondered what are the types of silicon chips or how it is manufactured, which techniques are used to manufacture it, etc? If you haven’t, we have covered all those topics in this article.

Silicon Chips:

Silicon or other semiconductor materials can be single crystalline, multicrystalline, polycrystalline or amorphous. The key difference between these materials is the degree to which the semiconductor has a regular, perfectly ordered crystal structure, and therefore semiconductor material may be classified according to the size of the crystals making up the material.

Types of Silicon Chips:

As mentioned above, there are various types of silicon chips and each one of them is different when compared with the other. The growth techniques to manufacture each type of silicon chip is also different. Following are the types and methods of growth techniques for silicon chips:

1. Single Crystal Chips:

Single crystal chips are those silicon chips which have grain size of less than 10 cm. Some of the most common growth techniques for single crystal chips are Czochralski technique (CZ) and Float zone technique.

A. Czochralski technique (CZ): This is the dominant technique for manufacturing single crystals. It is especially suited for the large wafers that are currently used in IC fabrication. Various components of this process are furnace, crystal pulling mechanisms, ambient control, control system etc.

B. Float zone technique: This is mainly used for small sized wafers. The float zone technique is used for producing specialty wafers that have low oxygen impurity concentration.

2. Multicrystalline Chips:

The material quality of multicrystalline material is lower than that of single crystalline material due to the presence of grain boundaries. Techniques for the production of multicrystalline silicon are more simple, and therefore cheaper, than those required for single crystal material. Some of the common methods of growth techniques used by multicrystalline chips are Cast, sheet, and ribbon.

3. Polycrystalline Chips:

The material quality of polycrystalline material is lower than that of multicrystalline material due to the presence of grain boundaries. Polycrystalline chips are 1µm-1mm in Grain size. Some of the common methods of growth techniques used by Polycrystalline chips is Chemical-vapour deposition.

4. Microcrystalline Chips:

The material quality of Microcrystalline material is lower than that of polycrystalline material due to the presence of grain boundaries. Microcrystalline chips are <1µm in Grain size. Some of the common methods of growth techniques used by Microcrystalline chips is Plasma deposition.