Background Statement for SEMI Draft Document 5775A New Standard: Specification for Sapphire Single Crystal Ingot Intended for Use for Manufacturing HB-LED Wafers Notice: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this Document. Notice: Recipients of this Document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, patented technology is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided. Background Statement Sapphire single crystal ingot is used as a substrate material for manufacturing HB-LED wafers. Despite the importance of sapphire single crystal ingot, however, there currently is no industry-consensus standard in LED industry for sapphire single crystal ingot. Such a standard would improve communication between users and suppliers, reduce costs, and increase productivity, so it is critical for the LED industry to come to consensus in the near future. Review and Adjudication Information Task Force Review Committee Adjudication Group: Sapphire Single Crystal Ingot Task Force HB-LED China TC Chapter Date: TBD Oct. 14th, 2016 Time & Timezone: TBD 9AM 4PM, Beijing time Location: TBD Friend Plaza Hotel Dandong City, State/Country: China Dandong, Liaoning, China Leader(s): Zijian An (Aurora) Yong Ji (GHTOT) Weizhi Cai (SANAN) Standards Staff: Kris Shen(SEMI China) Kris Shen(SEMI China) Meeting date and time are subject to change, and additional TF review sessions may be scheduled if necessary. Contact the task force leaders or Standards staff for confirmation. Check www.semi.org/standards for the latest schedule. If you have any questions, please contact the Sapphire Single Crystal Ingot Task Force. Zijiang An (Aurora) Tel: +86 18686756800/15765576610 E-mail: 66800@aurora-sapphire.cn Or contact SEMI Staff, Kris Shen at kshen@semi.org
SEMI Draft Document 5775A New Standard: Specification for Sapphire Single Crystal Ingot Intended for Use for Manufacturing HB-LED Wafers 1 Purpose 1.1 The purpose of this standard is to standardize the specification of sapphire single crystal ingot intended for use for manufacturing HB-LED wafers. 2 Scope 2.1 This specification includes the test methods and the requirements for key parameters and the defects of sapphire single crystal ingots. 2.2 The key parameters include the ingot diameter, flat height, surface orientation, flat orientation, surface scratch, surface roughness, vertical, cylindricity, straightness. 2.3 The defects need to be deducted include bubbles and cloud, crack, chip. NOTICE: SEMI Standards and Safety Guidelines do not purport to address all safety issues associated with their use. It is the responsibility of the users of the documents to establish appropriate safety and health practices, and determine the applicability of regulatory or other limitations prior to use. 3 Referenced Standards and Documents 3.1 None. 4 Terminology 4.1 Abbreviations and Acronyms 4.1.1 D diameter 4.1.2 H flat height 4.1.3 vertical 4.2 Definitions 4.2.1 Cylindricity Deviation between the maximum and the minimum diameter of the same circumference of a circle on the ingot cylindrical surface. 4.2.2 Straightness The difference of maximum and minimum distance between two intersection lines of one plane containing axis and the cylindrical surface. 4.2.3 Light Source Illumination of the white light source is 1800-3000 Lux. 5 Test Methods 5.1 Diameter In accordance with Appendix 1. 5.2 Flat Height In accordance with Appendix 2. 5.3 Surface Orientation In accordance with Appendix 3. 5.4 Flat Orientation In accordance with Appendix 4. 5.5 Surface Scratch By white light Source and vernier caliper. 5.6 Surface Roughness By roughness tester. 5.7 Vertical By bevel protractor. 5.8 Cylindricity In accordance with Appendix 5. 5.9 Straightness In accordance with Appendix 6. Page 1
5.10 Defects (Bubble and Cloud, Chip, Crack) Defects are inspected by light Source and deducted along the length of ingot correspondingly by vernier caliper. 6 Ordering Information 6.1 Purchase orders for sapphire ingot provided under this specification shall include the following items: 6.1.1 Diameter (D) and Flat Height (H) (The positions on ingot are shown in Figure 1). 6.1.2 Surface and Flat Orientation. 6.1.3 Total effective length of sapphire ingot after deducting defects. 6.2 The following items may be specified optionally in addition to those listed in Paragraph 6.1: 6.2.1 Vertical, Cylindricity and Straightness. 6.2.2 The limitation for the length percentage of ingot with defects. 7 Requirements Figure 1 The Positions of D and H on Ingot 7.1 Diameter The diameter size of ingot is agreed by customer and supplier. Allowable deviation range is ±0.1 mm. 7.2 Flat Height The flat height standard is made according to the requirement of diameter and flat length. For example: the requirement of 2 inch ingot is diameter 50.90 mm, flat length 16±1 mm, then the flat height standard is 49.61±0.16 mm; the requirement of 4 inch ingot is diameter 100.10mm, flat length 30±1 mm, then the flat height standard is 97.80±0.15 mm; the requirement of 6 inch ingot is diameter 150.20mm, flat length 47±1 mm, then the flat height standard is 146.42±0.16 mm. 7.3 Surface Orientation The surface orientation of the sapphire ingot is c-plane, and the accuracy of orientation is±0.1. 7.4 Flat Orientation The flat orientation of the sapphire ingot is a-plane, and the accuracy of orientation is± 0.2. 7.5 Surface Scratch Transverse scratches of length< 5mm paralleling to ingot end surface are allowed, the scratches vertical to end surface are rejected. 7.6 Surface Roughness Ra < 1.0 μm. 7.7 Vertical The vertical between the ingot surface and the flat: 0.1. The vertical between the ingot surface and the ingot body: 0.2. 7.8 Cylindricity The cylindricity of a 2 inch and 4 inch sapphire ingot is 0.02 mm, and the cylindricity of the 6 inch is 0.04 mm. Page 2
7.9 Straightness The straightness of a 2 inch and 4 inch sapphire ingot is 0.03 mm, and the straightness of the 6 inch sapphire single crystal ingot is 0.06 mm. 7.10 Bubble and Cloud The total length of the bubble and cloud should be less than 10% of the ingot length. 7.11 Chip The length of each chip along the ingot axis should be 1.5 mm. 7.12 Crack The length of each crack along the ingot axis should be 3 mm, and the crack paralleling to end surface is rejected. Page 3
APPENDIX 1 TEST METHOD FOR THE DIAMETER OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB-LED WAFERS A1-1 Procedure A1-1.1 Three different diameters of a circle at each end are measured by vernier caliper, as shown in Fig.2. A1-1.2 The maximum value is recorded as the diameter of this ingot. Figure 2 Diameter Measurement Positions of Sapphire Ingot with Length Page 4
APPENDIX 2 TEST METHOD FOR THE FLAT HEIGHT OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB- LED WAFERS A2-1 Procedure A2-1.1 The flat heights (see Fig.1) at both ends of sapphire ingot (see Fig.2) are measured and denoted by H 1 and H 2. A2-1.2 The larger of above two values is regarded as the flat height of this ingot. Page 5
APPENDIX 3 TEST METHOD FOR THE SURFACE ORIENTATION OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB-LED WAFERS A3-1 Procedure A3-1.1 Calibrate the X-ray diffractometer and adjust the ammeter to make the maximum peak reaching 70-80μA. A3-1.2 Adjust the θ of the orientation device to 20 50 and 2θ to 41 40, which is the sapphire feature peak of c- plane A3-1.3 The end face of sapphire ingot must be parallel and cling to the measuring board with no gap in order to get the accurate measuring data during measure surface orientation of the sapphire ingot. A3-1.4 Roll the handle to change the θ and observe the data on ammeter, when the ammeter s pointer points to 70-80μA, record the angle θ, which is the surface orientation of sapphire ingots. A3-1.5 Measure θ on both ends of the sapphire ingot, and the maximum value is regarded as the effective value. Page 6
APPENDIX 4 TEST METHOD FOR THE FLAT ORIENTATION OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB- LED WAFERS A4-1 Procedure A4-1.1 Calibrate the X-ray diffractometer and adjust the ammeter to make the maximum peak reaching 70-80 μa. A4-1.2 Adjust the θ of the orientation device to 18 55 and 2θ to 37 50, which is the sapphire feature peak of a- plane. A4-1.3 The flat of sapphire ingot must be parallel and cling to the measuring board with no gap in order to get the accurate measuring data during measure the flat orientation of the sapphire ingot. A4-1.4 Roll the handle to change the θ and observe the data on ammeter, when the ammeter s pointer points to 70-80μA, record the angle θ, which is the flat orientation of sapphire ingots. A4-1.5 Measure θ on both ends of the sapphire ingot, and the maximum value is regarded as the effective value.. Page 7
APPENDIX 5 TEST METHOD FOR THE CYLINDRICITY OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB- LED WAFERS A5-1 Procedure A5-1.1 Measure both ends diameter of sapphire ingot (Fig.2) A5-1.2 Three diameter measuring points on one end is indicated as (a 1 a 2 ), (b 1 b 2 ), and (c 1 c 2 ) respectively. A5-1.3 The maximum is recorded as MAX and the minimum as MIN, then the difference between MAX and MIN is calculated. A5-1.4 The difference of another end is calculated in the same way. A5-1.5 The larger of above two values is regarded as the cylindricity of this ingot. Page 8
APPENDIX 6 TEST METHOD FOR THE STRAIGHTNESS OF SAPPHIRE SINGLE CRYSTAL INGOT INTENDED FOR USE FOR MANUFACTURING HB- LED WAFERS A6-1 Procedure A6-1.1 Measure both ends diameter of sapphire ingot (Fig.2). A6-1.2 Six diameter measuring points on both ends is indicated as (a 1 a 2 ), (a 1 a 2 ), (b 1 b 2 ), (b 1 b 2 ), (c 1 c 2 ) and (c 1 c 2 ) respectively. A6-1.3 The absolute values of diameter differences on corresponding position of both ends, (a 1,a 2 )-(a 1,a 2 ), (b 1,b 2 )-(b 1,b 2 ) and (c 1,c 2 )-(c 1,c 2 ), are calculated. A6-1.4 The largest of three above value is regarded as the straightness of this ingot. NOTICE: (SEMI) makes no warranties or representations as to the suitability of the Standards and Safety Guidelines set forth herein for any particular application. The determination of the suitability of the Standard or Safety Guideline is solely the responsibility of the user. Users are cautioned to refer to manufacturer s instructions, product labels, product data sheets, and other relevant literature, respecting any materials or equipment mentioned herein. Standards and Safety Guidelines are subject to change without notice. By publication of this Standard or Safety Guideline, SEMI takes no position respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this Standard or Safety Guideline. Users of this Standard or Safety Guideline are expressly advised that determination of any such patent rights or copyrights, and the risk of infringement of such rights are entirely their own responsibility. Page 9