Silicon dioxide wafer can be offered by PAM-XIAMEN, which is single / double side polished and one-sided / double-sided oxidation in various sizes. In the integrated circuit process, oxidation is an indispensable process technology. Since early people discovered that the diffusion rate of impurity elements such as boron, phosphorus, arsenic, and antimony in SiO2 is much slower than the diffusion rate in Si, SiO2 film has been widely used as a mask for selective diffusion in device production, and has promoted the emergence of silicon planar technology. At the same time, the SiO2 film grown on the Si surface not only has good adhesion to Si, but also has very stable chemical properties and electrical insulation. Therefore, thermal oxide silicon wafer plays an extremely important role in integrated circuits. The specifications of SiO2 wafers you can buy are as following:
1. Specifications of Silicon Dioxide Wafer
|No.||Size (inch)||Type||Orientation||Thickness(um)||SiO2 (nm)||Resistivity Range (ohm-cm)||Surface Processed|
|PAM-01||1||P||100||525±10||330nm||0-0.005||1 side polished, 2 sides oxidation|
|PAM-02||2||P||100||500±20||3um||1-10||1 side polished, 2 sides oxidation|
|PAM-04||2||N||100||285±15||1um||1-10||2 sides polished, 2 sides oxidation|
|PAM-09||3||FZ||100||400±10||2um||10000-20000||1 side polished, 2 sides oxidation|
|PAM-015||4||/||100||400±10||2um||10000-20000||1 side polished, 2 sides oxidation|
|PAM-025||4||P||100||400±10||500nm||3000-5000||1 side polished, 1 side oxidation|
|PAM-035||4||N||100||500±25||270/320nm||0.01-0.05||1 side polished, 2 sides oxidation|
|PAM-036||4||P||100||700±10||300-310nm||0.001-0.002||1 side polished, 2 sides oxidation|
|PAM-037||4||P||100||700±10||305±5nm||0-0.1||1 side polished, 2 sides oxidation|
|PAM-052||4||P||100||500±20||150nm||0-0.0015||1 side polished, 2 sides oxidation|
|PAM-054||4||P||111||500±25||50-80nm||0-0.05||1 side polished, 2 sides oxidation|
|PAM-056||6||N||100||510±15||200nm||6000-10000||1 side polished, 2 sides oxidation|
|PAM-057||6||P||111||645±25||500nm||5-25||1 side polished, 2 sides oxidation|
|PAM-059||6||/||100||650±25||500nm||5000-10000||2 sides polished, 1 side oxidation|
|PAM-060||6||P||100||675±25||500nm||0.5-100||1 side polished, 2 sides oxidation|
|PAM-061||6||/||100||625±25||2um||1-100||1 side polished, 2 sides oxidation|
|PAM-062||6||N||100||650±50||2.8um||0.1-100||1 side polished, 2 sides oxidation|
|PAM-066||8||P||100||720±25||100-500nm||0.005-100||1 side polished, 2 sides oxidation|
|PAM-070||5||N||100||525±15||300nm||0-0.005||1 side polished, 1 side oxidation|
|PAM-084||6||P||100||675±25||8um±5%||10-20||1 side polished, 2 sides oxidation|
|PAM-086||12||P||100||650±50||100-500nm||1-100||2 sides polished, 2 sides oxidation|
2. Silicon Wafer Oxidation Process
The oxidation process of silicon dioxide on silicon wafer is a surface process, that is, the oxidant reacts with Si atoms on the surface of the silicon wafer. When the SiO2 layer formed on the silicon surface prevents the oxidant from contacting directly with Si, the oxidant must diffuse through the SiO2. When the layer reaches SiO2, a silicon dioxide wafer interface reacts with Si atoms to form a new SiO2 layer, making the SiO2 film thicker, and at the same time, the SiO2-Si interface advances into the Si.
3. Influencing Factors of Silicon Wafer Oxide Layer Growth Rate
There are many factors, such as oxidation source, atomic density, temperature and etc. will affect silicon wafer thermal oxide growth rate.
The atomic density is different, so under the same temperature, oxidation pressure and other conditions, the crystal plane with high atomic density has a higher oxidation growth rate for silicon oxide wafer, and the linear stage at low temperature is more obvious.
The effect of silicon wafer oxide temperature can be seen from the relationship between the parabolic velocity constant B and the linear constant B/A and temperature. As shown in the following Table, the values of A, B, and B/A under different oxidation atmospheres and different temperatures are given.
|Dry oxygen oxidation||1200||0.04||7.5 x 10-4||1.87 x 10-2|
|1100||0.09||4.5 x 10-4||0.50 x 10-2|
|1000||0.165||1.95 x 10-4||0.118 x 10-2|
|920||0.235||0.82 x 10-4||0.0347 x 10-2|
|Wet Oxygen Oxidation
(95℃ water vapor)
|1200||0.050||1.2 x 10-2||2.40 x 10-1|
|1100||0.11||0.85 x 10-2||0.773 x 10-1|
|1000||0.226||0.48 x 10-2||0.212 x 10-1|
|920||0.50||0.34 x 10-2||0.068 x 10-1|
|Water Vapor Oxidation||1200||0.017||1.457 x 10-2||8.7 x 10-1|
|1094||0.083||0.909 x 10-2||1.09 x 10-1|
|973||0.3550||0.520 x 10-2||0.146 x 10-1|
4. Quality Assessment for the Silicon Dioxide Wafer
After oxidation, the quality of silicon wafer with oxide layer should be evaluated. Because some of the tests are destructive, a certain number of samples specially used for testing are placed in different positions while sending a batch of crystal gardens into the furnace tube. Generally, it mainly includes surface inspection and thickness inspection of the thermal oxide growth silicon wafers. Surface inspection is usually performed on each silicon wafer with SiO2 under high-brightness ultraviolet light, including surface particles, irregularities, and stains that will appear under ultraviolet light.
The detection of silicon wafer oxide thickness is very important due to the requirements of different devices or different purposes. For example, the thickness of the MOS gate oxide layer is very strict. The detection techniques for silicon dioxide wafer include: color comparison, edge counting interference, ellipsometry and scanning electron microscope, etc.