Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100 Meta Description: Know all about the benefits of silicon wafer etching technique using Olympus LEXT OLS5100 laser confocal microscope for micro-texturing of the silicon front surface to improve the performance of solar panels, and the potential gains it can offer solar parks across India.

Silicon Wafer Etching using Olympus LEXT OLS5100

Government initiatives such as the National Solar Mission are clear indicators that the country is prioritizing meeting its energy demands through renewable sources of energy as opposed to the non-renewable counterparts. The Indian Government aims to achieve a total installed solar capacity of 20 GW by 2022. India has set up over 40 major solar plants that generate a whopping 10+ MW of solar energy to keep the nation thriving, Including the World’s Largest Solar Plant namely, Bhadla Solar Park in Rajasthan’s Jodhpur District. The increasing solar strength and opportunities in the country can be depicted by the following infographic. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon based solar cells dominate the current photovoltaic market and are preferred by the solar cell industries. Si substrate is used as material for solar cells and microelectromechanical systems (MEMS) and integrated circuit (IC) manufacturing .Because of its environment friendliness, , paramount availability in abundance after oxygen ,high temperature, minimal price, limited current leakage, stability and also low and high power handling capacity. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon wafer etching is a process to improve light trapping by modifying surface reflectivity of silicon wafer and use it for solar panel manufacturing. This process is called Micro-texturing of the silicon front surface. An alkaline solution is used for the etching process,which is also widely used to form micro-sized pyramidal structures on the silicon surface. Measurement of surface roughness and surface area become important parameters as they increase with increase in etching time depending on the process. So these parameters help us to understand and optimise process required to get desired etching. Silicon Wafer Etching using Olympus LEXT OLS5100

To measure height of pyramids by Conventional techniques like SEM we need to cut samples to see the cross section which makes the process tedious and is not cost effective.

To overcome this we are introducing an easy yet sophisticated solution to the aforesaid problem using Olympus OLS5100 laser Confocal Microscope. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Benefits of Using Laser Microscope for measuring the height of pyramids in textured silicon substrate during the Silicon Wafer Etching process.

Submicron Level 3D Observation & Measurement: The LEXT OLS5100 confocal laser microscope enables users to observe submicron unevenness and measure it accurately, giving the end user a closer look of the silicon wafer’s texture.

Surface Roughness Measurement: This device allows ISO compliant level measurement of the silicon wafer’s surface roughness. The user can go to arial from line profile enabling a new standard of roughness measurement.

Speedy: This is a non-contact, non-destructive technique of measurement which requires no processing. You can start to measure from the moment you put your sample under the lens.

Functional Capabilities of Laser Scanning Microscope (Silicon Wafer Etching using Olympus LEXT OLS5100)

Silicon Wafer Etching using Olympus LEXT OLS5100

Etched Silicon Wafer Image @ 2000x Zoom

Silicon Wafer Etching using Olympus LEXT OLS5100

Olympus OLS5100 captures height of individual peak using profile line and maximum peak for specific region as Sp value other important parameters to understand surface texture are surface roughness, surface area and volume of pyramid .There is need to destroy sample and it’s also non-contact so no contamination is induced during analysis. Silicon Wafer Etching using Olympus LEXT OLS5100

Measurement of Height (Silicon Wafer Etching using Olympus LEXT OLS5100)

Measurement of Volume

Olympus OLS5100 laser confocal Microscope provides us Volume and surface area for peak and valley. An ideal silicon wafer will have a homogeneous peak in height and volume and no blank zone as a valley.We can measure the volume of peaks separately to understand individual peak volume and its average so that we can optimize the etching process to achieve homogeneous peaks. Volume of the valley can also be measured as a separate value so that one can understand the process where you have a minimum black zone as a valley. White region in any laser image is a blank undesired region. Similarly, we have surface area to guide us for optimization on the etching process for desired peak and reduced blank zone as valley. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Where Spd represents the density of peaks per unit area. Spc represents the arithmetic mean of principal curvature of the peak of surface.

Silicon Wafer Etching using Olympus LEXT OLS5100

Std This parameter indicates the direction angle of the texture. Therefore, we understand that pyramid like structure in given silicon wafer has angle of 99.6 deg

The PSD parameter helps us to understand the periodicity of the pyramid.

The LEXT OLS5100 Microscope’s Smart Experiment Manager.

Helps make your experiment workflow simpler by automating time-consuming tasks.

  • Automatically creates your experiment plan
  • Auto populates data to your experiment plan matrix, reducing the chance of input errors
  • Clear data trend visualization tools

Olympus OLS5100 laser confocal microscope automatically captures multiple regions on silicon wafer and helps us understand how surface area and surface roughness is changing . It eases the analysis process as it populates all data on one sheet as a head map which eliminates the need to open files individually.

Silicon Wafer Etching using Olympus LEXT OLS5100

Author- Gyanesh Singh Application Specialist at IR Technology Services Pvt. Ltd Passionate about Microscopy for Micro and Nanostructures. Gyanesh has over 10 years of experience in demonstration and serving application of various techniques to potential clients and enjoys learning new sophisticated scientific technology for Material Science and Life Science.

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