Recent Progress in SEMI Standards Global Traceability Technical Committee Activity
By Andy Ohwada, Adem Ltd
In late October 2011, good news was brought by Yoichi Iga, co-chair of the Japan Traceability Technical Committee in one of our Task Force meetings. According to him, our document 4845A (Published as SEMI T21) and document 4847A (Published as SEMI T22) were balloted and passed at the Committee meeting. This will finalize the long chain of SEMI Traceability Standards. Mr. Iga is a Senior Expert for Quality Assistance Div., Renesas Electronics Corp. and another co-chair for our committee is of course Hirokazu Tsunobuchi, Senior Manager for Auto ID Div., Keyence Corporation.
Now, SEMI owns and provides one of the best Traceability System known in the industry as this report explains in detail. One strength among many found in these Standards is that all ID listed are two dimensional codes, which make them searchable and it is physically imprinted on the individual body, by which the method makes ID inerasable.
With regards to the chips, all the records of their major steps of semiconductor manufacturing and logistics processes to reach this point are possible and made available to responsible parties.
First, Silicon ingot pulled from its furnace of its material manufacturer is a starting point of a long process of semiconductor device. The manufacturer slices the ingot into wafers. The back side of each wafer can carry 2D information in line with SEMI T7, Specification for Back Surface Marking of Double-Side Polished Wafers with a Two-Dimensional Matrix Code Symbol. SEMI T7 shows such information as P-type or N-type, resistivity, unique individual wafer ID attached to the ingot, ingot ID and manufacturer's name among lot other information.
A semiconductor device manufacturer can purchase the wafers from such ingot and wafer manufacturers. The device manufacturer will place wafers into one of its wafer fabs per the company’s manufacturing order, and then lot start order (LSO) is released and the fab lot is organized with wafers mentioned above. SEMI T7 ID can be used as wafer ID in the fab until back grind process erases the ID. However, we have created SEMI T14. SEMI T14 is another 2D code with 6 micron dots marked onto bevel portion near front surface of each 300 mm wafer. A laser beam can melt Si crystal and then the liquid part undergoes crystallization when laser is “off”, forming an elevated portion, or dot at the spot. So, SEMI T14 can carry Lot #, Wafer #, Fab information and Date code of the start up date, among other information that the maker decides.
After Wafer Fab process, it can move to multi probe process where the maker tests device functions for all the dies. Before or after probe, ID may be marked physically using SEMI T19 on each good die, except bad ones, which will be discarded. Using SEMI T19 after probe, the maker may include test result into the SEMI T19 ID, or “bin” information. The device will go through packaging and then final marking processes. To apply the final marking, SEMI T20.1 exists. SEMI T20.1 is a specification for Object Labeling to authenticate semiconductors and related products in an open market.
The last two standards are above mentioned SEMI T21 and SEMI T22. SEMI T21 is specification for Organization Identification by Digital Certificate Issued from Certificate Service Body (CSB) for Anti-Counterfeiting Traceability in Components Supply Chain; and T22 is specification for Traceability by Self Authentication Service Body (SASB) and Authentication Service Body (ASB). Reliability of CSB, SASB and ASB are naturally very high.
An automotive maker procures engine control units or ECU modules from an advanced automotive module and system manufacturer. Modules and systems manufacturer buys ECU chips from semiconductor manufacturer. Chips and module products will be shipped to each customer through logistics channel, when device authenticity and product purity will be kept. A late model car made in Japan, carries beyond hundreds of semiconductor devices. Try to imagine a vehicle finished all of the factory processes and marching through the final decorated pathway into a long hauling truck waiting at the shipping dock!! This way, SEMI Traceability Standards System keeps continuous traceability on semiconductors.
Now in particular, we appreciate extensive contribution from our North America colleagues in the Global Traceability Technical Committee, who gave us the following comments upon release of SEMI T21 and SEMI T22.
“Traceability within supply chains is imperative for the global economy, security and human health. It is apriority area of concern for the U.S. Government. The work of the Global Traceability Technical Committee will enable traceability in the electronics components supply chain, which underpins the global economy. We are very proud of the accomplishments of the Global (Japan + North America) Traceability Technical Committee.” Yaw S. Obeng, Ph. D., MBA Senior Scientist,
Measurement Lab National Institute of Standards and Technology
“The Traceability standards continue to improve every year. Now, the completion of SEMI T21 & SEMI T22 empower and helps customers to utilize the entire T-standards suite to resolve electronic component quality and reliability issues more efficiently. SEMI T21 and SEMI T22 create a bridge between SEMI industry members and any other industry that uses semiconductor products.” David A. Brown, Senior Principal Engineer Intel Corporation.
The trend of frequent incident of counterfeit chips needs to be controlled. In view of good reliability attached to traceable chips.
Regarding fake chips, the U.S. Senate Armed Services Committee has found that counterfeit electronic parts are finding their way into the U.S. military supply chain at an alarming rate.
Before issuing any PO, buyers and users can depend upon information concerning origin of semiconductor products using specific URL in the net.
Figure: Image of Searching Traceability Information in SEMI T21
Japan Traceability Technical Committee
Japan Anti-Counterfeiting Task Force/ Device Security Task Force
SEMI Standards Watch, March 2012