Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone: 408.943.6900, Fax: 408.943.7943
hb khghgh1000A
Background Statement for SEMI Draft Document 5429
NEW STANDARD: TEST METHOD FOR IN-LINE MONITORING OF FLAT TEMPERATURE ZONE IN HORIZONTAL DIFFUSION FURNACE
Note: 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.
Note: 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
Horizontal diffusion furnace is a key device in the solar cell manufacturing process, and its role is to dope some trace elements (such as phosphorus, boron, etc.) into the wafer to form a PN junction at high temperature and under a certain pressure. In the diffusion process, the diffusion furnace temperature zone is the most important factor affecting the performance of diffusion, therefore testing of the temperature zone is very crucial.
Currently, there are differences in the testing principle, devices and methods in the testing flat temperature zone. This gives users and manufacturers inconsistencies, thus this standard will define the test method of flat temperature zone in horizontal diffusion furnace.
Review and Adjudication Information
Task Force Review / Committee AdjudicationGroup: / China PV Diffusion Furnace Test Methods TF / China PV Committee
Date: / TBD / March 20th, 2014
Time & Timezone: / TBD / 9:00--18:00
Location: / TBD / Kerry Hotel
City, State/Country: / Changsha, China / Shanghai, China
Leader(s): / Liangyu Liu（48th Institute)
Xianwu Cai (48th Institute)
Cao Qian(48th Institute)
Yu Si (SevenStar) / Guangchun Zhang (Canadian Solar)
Jun Liu (CESI)
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 for the latest schedule.
If you have any questions, please contact the ballot author at:
Hui Long / 48th Institute
Tel: +86 159 7429 1515
E-mail:
SEMI Draft Document 5429
NEW STANDARD: TEST METHOD FOR IN-LINE MONITORING OF FLAT TEMPERATURE ZONE IN HORIZONTAL DIFFUSION FURNACE
1 Purpose
1.1 This document covers the test method of flat temperature zone in horizontal diffusion furnace including the testing principle, testing devices, environment, testing steps and the calculation of the flat-temperature zone.
2 Scope
2.1 This test method is intended for testing flat temperature zone in horizontal diffusion furnace. Horizontal PECVD equipment, horizontal vacuum annealing furnace, horizontal alloy furnace and other similar equipments can also be implemented by reference.
2.2 This test method can be applied to evaluate the performance of the heater tube in horizontal diffusion furnace.
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 ISO Standard[1]
ISO 14644-1 — 1999 — Clean rooms and Associated Controlled Environments —Part 1: Classification of Air Cleanliness
3.2 China National Standards[2]
GB/T 1598 — 2010 — Platinum-10%Rhodium/Platinum Thermocouple Wires, Platinum-13% Rhodium/Platinum
Thermocouple Wires, Platinum-30%Rhodium/Platinum-6%Rhodium Thermocouple Wires
NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.
4 Terminology
4.1 Refer to the SEMI Standards Compilation of Terms (COTs) for a list of the current Abbreviations, Acronyms, Definitions, and Symbols.
4.2 Definitions
4.2.1 Tp — the working temperature which is needed to reach in the diffusion process.
4.2.2 Δt — the allowable deviation of the flat-temperature zone temperature.
4.2.3 Tmax — the maximum coordinated temperature value in the flat-temperature zone. In other words, process temperature Tp plus Δt( Tmax= Tp+Δt).
4.2.4 Tmin — the minimum coordinated temperature value in the flat-temperature zone. In other words, process temperature Tp minus Δt( Tmax= Tp-Δt).
4.2.5 Ti — the temperature detected by thermocouple in the i position.
4.2.6 Flat-temperature zone—consecutive temperature area in which the each Ti between Tmax and Tmin along the axial direction of the furnaces.
4.2.7 In-line monitoring — the testing of flat-temperature zone under the process temperature and process gas flow rate (Suggested: 25 SLM).
4.2.8 Ld — the design length of flat temperature zone in furnace.
4.2.9 Lf — the longest length of flat temperature zone in furnace.
4.2.10 Δl — the step length between two test point.
5 Summary of Test Method
5.1 This test method uses the single point measuring. A single thermocouple is driven to measure the flat temperature zone of horizontal diffusion furnace by a linear motion mechanism (such as linear motors, linear modules, etc.). The principle is shown in Figure 1. The thermocouple measuring terminal extends into the furnace body of the horizontal diffusion furnaces, and the other terminal is fixed to the moving parts of the linear motion mechanism by a clamp. The base of the linear motion mechanism is immobile, and the left side of the base is equipped with a thermocouple support base which is located on the central position of the thermocouple to support the thermocouple avoiding thermocouple fracture. This measured temperature value is collected by temperature data logger. The Industrial Personal Computer (IPC) is used to control the linear motion mechanism and the temperature data logger.
1- tail thermal insulation cotton; 2- ring-shaped thermal insulation cotton; 3- thermal insulation cotton of heater; 4-heating wire; 5-quartz tube; 6-wafer; 7-quartz loader; 8-temperature detection point; 9- ring-shaped thermal insulation cotton; 10-end ring-shaped thermal insulation cotton ; 11-sealing quartz door; 12- door thermal insulation cotton; 13- thermocouple; 14a- the moving parts of the linear motion mechanism; 14b- the base of the linear motion mechanism; 15-clamp; 16- parts for supporting thermocouple
Figure 1
The Diagram of Test Principle
6 Test Conditions
6.1 The test conditions must meet the following requirements:
6.1.1 Ambient temperature : 5 °C ~ 40 °C
6.1.2 Relative humidity <75%
6.1.3 Voltage fluctuations do not exceed rating of ± 10%
6.1.4 Environmental cleanliness should be better than 8 grade clean room requirements as defined in ISO 14644-1-1999 “Cleanrooms and associated controlled environments--Part 1:Classification of air cleanliness”
6.2 Sufficient space between the diffusion furnace and gas source cabinet should be allowed to meet the installations of linear motion mechanism and thermocouple mobile.
6.3 The tested horizontal diffusion furnace should be mounted stationary and the centerline of diffusion furnace should maintain level.
6.4 The testing is required in the process temperature and under the rated flow of the process gas（Suggested ：25 SLM）.
7 Apparatus
7.1 Test devices must be approved by the professional metrology institutes and certified within the validity period.
7.1.1 Temperature controller (accuracy: 0.1 °C);
7.1.2 Thermocouple (platinum and rhodium alloy thermocouple, accuracy class is higher than defined levelⅡ in GB/T 1598-2010 “Platinum-10%Rhodium/Platinum thermocouple wires, Platinum- 13%Rhodium/Platinum thermocouple wires, Platinum-30%Rhodium/Platinum-6%Rhodium thermocouple wires”
7.1.3 Thermocouple compensating conductor(copper-coppernickel compensating conductor);
7.1.4 Linear motion mechanism (such as linear motors, linear modules, etc.);
7.1.5 Clamp;
7.1.6 Thermocouple support base;
7.1.7 Industrial Personal Computer (IPC).
8 Procedure
8.1 Put the thermocouple (see Figure 2) into the quartz tube. The special thermocouple measuring terminal extends into the quartz tube, and the other terminal is fixed on the moving parts of the linear motion mechanism through a clamp (see Figure 1).
8.2 Connect the thermocouple with the temperature data logger by a copper-coppernickel compensating conductor, refer to Figure 3.
8.3 Starting horizontal diffusion furnace and inlet the rated process gas flow. Heat the furnace up to process temperature Tp and remain stable for 2 hours so that the temperature becomes stable.
8.4 Start up linear motion mechanism and drive the special thermocouple to make it moving from the quartz tube orifice to the end . The use of IPC is to control the running speed of the linear motion mechanism. The thermocouple stay 6 min per moveΔl mm (Note: Δl = Ld / n, n≥30) . Simultaneously, the temperature controller collects the temperature Ti of the position i and sends the data to IPC.
8.5 Draw the temperature curve base on the measured temperature of each point value, the abscissa shows displacement distance and the vertical coordinates shows the measured temperature value.
NOTE 1: The test area should cover the design flat temperature zone.
Figure 2
The Thermocouple Sketch Map
Figure 3
The Connection Diagram of Temperature Controller
9 The Calculations of Flat Temperature Zone
9.1 Suppose figure 4 shows the measured temperature curve. Tp, Tmax and Tmin are respectively the process temperature, the maximum and the minimum coordinated temperature value of the flat-temperature zone separately. The temperature zones L1, L2, and L3 are within the permissible range, while the L2’s length is the longest one. In accordance with the definition of the flat-temperature zone length, L2 is the length of flat-temperature zone(Lf) in the horizontal diffusion furnaces.
Figure 4
Temperature Curve
10 Testing Report
10.1 The testing report should include at least the following elements:
10.1.1 The model name of horizontal diffusion furnace;
10.1.2 The type and model name of the detection equipment;
10.1.3 The testing environment and conditions;
10.1.4 Testing basis;
10.1.5 Testing results;
10.1.6 Testing dates and personnel;
10.1.7 Authorized stamp of testing units.
NOTICE: Semiconductor Equipment and Materials International (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.
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline. Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 1Doc. 5429 SEMI
[1] International Organization for Standardization, ISO Central Secretariat, 1 rue de Varembé, Case postale 56, CH-1211 Geneva 20, Switzerland. Telephone: 41.22.749.01.11; Fax: 41.22.733.34.30;
[2] China National Standards， Standardization Administration of the People's Republic of China ，No.9 Madian Donglu， Haidian District， Beijing，China. Telephone: +86-10-82262609; Fax: +86-10-82260684 ; http://www.sac.gov.cn/