Page 1 Sapphire Training Report in Mineral ~

Page 2 Sapphire Training Schedule Growth Anneal /Cooling Detach Reload Seeding Detach Growth Anneal /Cooling Reload Seeding Growth Detach 1 st Ingot 2 nd Ingot 3 rd Ingot In the duration of the training, we can participate: 1. the detachment of ingot for three times. 2. the reloading of raw material for two times. 3. the seeding for two times. Three ingots will be produced during training but the cylinder process will be done on the other ingot. The purity of the raw material which is being using by Mineral for producing during training is %. And the raw material with purity of can be arrived to Mineral around 7/M.

Page 3 Sapphire Training on 6/6  Check Grower Status The temp. between left and right wall should be less than 1 ℃. If this value is large than 15, it means the crystal starts to touch crucible. When it happens, the technologist will adjust the position of the rod to avoid the crystal sticking the crucible.

Page 4 Sapphire Training on 6/6  Software Description 1.Got the software and process parameter settings from Mihkail. However, some words are changed to strange symbols when the software is executed on our PCs even the language setting is changed to Russia. 2.Got the software of “Delphi 7” in order to compile the grower software. There are two components of Delphi 7 necessary for compiling Cport: work with computer TsiLang: Change language 3.The process parameter settings provided by Mihkail must be different from that used in real production because the “pulling rates” of the growth stage are missing. Will check with Mihkail and try to get the real settings.

Page 5 Sapphire Training on 6/6  Explanation of Process Stages 1.The raw material to be loaded into the crucible can be two types: Compacted powder with the density over 3.3 g/cm^3 and the diameter of 200~210mm and the height the same as the crucible. 20% Verneuil chuck and 80% powder. 2.If the purity of the raw material is not high, it’s color under Hg UV lamp will be pink. 3.However, Mineral is not capable to distinguish the material with purity of % and %. 4.Normally, the pulling speed at each stage is as following: Shouldering: 0.3mm/hour Growth: 0.1mm/hour Annealing: 0.5mm/hour

Page 6 Sapphire Training on 6/7  Seeding Stage Explanation 1.The heater will be deformed, therefore, the convention flow shown as below is ideal. 2.The actual convention flow is as below. The dark lines are cold and it’s recommended to seeding at the intersection of convention lines. The timing to seed is when the distance between two convention lines is from 15mm to 20mm. Seeding location 15~20mm

Page 7 Sapphire Training on 6/7  Seeding Stage Explanation 3.It has to form several “constrictions” (neck) in order to get the sapphire with good quality. When the growth rate is stabilized and slow enough (2mm enlarging in the horizontal direction within 30mins), the seeding stage is complete and the shouldering stage starts. Constriction

Page 8 Sapphire Training on 6/8  Explanation of Forming and Handling Parasitical Crystal 1.When the island/contamination appears on the melt surface, it moves toward the crystal due to convention flow and surface area force. Finally, the island/contamination sticks onto the crystal as a second seed so called “parasitical crystal”. It’s possible to remove the parasitical crystal by making a wave. Making a wave is to move the rod in the direction opposite to the parasitical crystal and move it back forcefully. Please be noted that a wave can be made only after the diameter of the parasitical crystal is larger than 15mm. The parasitical crystal sinks into the melt after covered by the wave due to it’s weight. If the wave couldn’t remove the parasitical crystal, it’s necessary to melt the seed and make constrictions again. Contamination Rod 5mm distance between rod and sylphon.

Page 9 Sapphire Training on 6/8  Shouldering Stage Explanation 1.After the growth rate stabilized, it’s time to make a shoulder. The pull speed decides the shoulder shape. The top of shoulder can’t be flat, otherwise, the ingot will break during processing. It’ s recommended to have the pull speed of 0.3mm/hour for shouldering and decrease to 0.1mm/hour when the weight of the ingot reaches to 5kg which means the shouldering stage is finished. 16 cm