Crystal Growth
We use the Czochralski (CZ) method to grow both p-type and n-type dislocation-free silicon ingots with <100>, <111> or <110> orientation. The diameters of the ingots are 75mm,100mm,125mm, 150mm,200mm and 300mm. The dopant types used, and the matching resistivity ranges for each dopant are listed in the product tables. 

Slicing
Slicing follows the process of cutting the ingot into thin wafer slices. Homray Material Technology used cutting-edge wire and I.D. saws that are operated by experienced and well-trained operators to produce high quality wafers. The techniques to achieve thin wafers with low kerf loss are applied, which help to ensure wafer flatness and total thickness variation (TTV) is controlled to minimum.

Edge Grinding
After slicing process, Homray Material Technology used edge grinding technology to create rounded edges on each wafer. The purpose of this step is to minimize edge chipping, breakage and thermal induced slip in the subsequent customer's thermal processes. Based on different Epi thickness and/or processes, an optimized edge profile and length can be made with specific customer specifications.

Lapping
Lapping is the process where residual slicing damage on the wafer's surface has removed. Initial refinement on wafer flatness is also conducted during this process.

Etching
Both acid and caustic etching are available according to customer's requirements. The damaged layers caused by the previous processes are removed during etching process. We can also provide a residual damage layer during the caustic etching process for backside gettering purposes. Special shape control can be achieved with state-of-the-art etching machines and techniques.

Backside Treatment
To satisfy customer detailed requirements, Homray Material Technology is capable of adding LTO, poly-back, or backside damage (BSD) to the backside of wafers. These treatments help to ensure high device yield. For thick poly-back, Homray Material Technology has developed a unique patented process to ensure wafer flatness.

Polishing
Polishing techniques have a big impact on the outcome of the wafer's surface, which is why Homray Material Technology uses sophisticated polished and a rigorous inspection process to produce world-class silicon wafers. Homray Material Technology is able to perform tight roughness wafer surface.

Cleaning
The cleaning process removes surface metals as well as micro particles away from wafer surface. Homray Material Technologys' engineering group has conducted various experiments that help to modify our cleaning process to perfection stage.

Visual Inspection
In order to supply defect-free products to our customers, we have conducted visual inspection on each wafer in the drak room with the assistance of the auxiliary light sources.

Wafer Characterization
After the wafer has undergone polishing and cleaning procedures, we use advanced equipment and cutting-edge technology to accurately measure the wafer's resistivity, thickness, TTV, STIR, bow and warp, etc. according to customer's requirements.

Wafer Clearance Inspection
To ensure we are delivering high quality wafers to customers, we use precise, state-of-the-art machines that accurately measure particle count on the wafer's surface before packaging.

Package
The wafers are desiccated with a nitrogen purge to evacuate humidity down, tape sealed, double bagged (PE + Aluminum Bag), and then vacuum packed in a class 10 clean room environment.