In order to achieve high quality vlsi chips, you must employ a rigorous testing strategy. This paper describes the present status of iddq testing along with the. Bipartite, differential iddq testable static rani design. Malaiyat electrical engineering department t computer science department colorado state university fort collins, co 80523 abstract iddq or current testing has emerged in the last few years as an effective technique for detecting certain. Cmos testing 2 design and test design for testability dft scan design builtin self test iddq testing. A method for iddq testing to detect defects in a semiconductor device in the presence of a high background leakage current. Elec7250001 spring 2006 vlsi testing, final grading table elec7250001 spring 2005 vlsi testing, final grading table graph elec 7250 spring 2004. This thesis also provides test procedure and results for the each test. Gulati, 9780792393153, available at book depository with free delivery worldwide. Although an iddq test makes no direct query of a devices ability. Roadmap for semiconductors projects that iddq levels will rise rapidly with each technology advance 45.
Digital test methods iddq tutorial iddq tutorial goals. An important factor in the acceptance and use of iddq testing as a way to detect defects in digital cmos integrated circuits is the methods ability to enhance the fault coverage of an overall test program with a small number of additional test vectors. In general, functional, structural, and parametric tests are complementary in nature and integral components of a test. As faultfree and faulty iddq distributions overlap, it is not clear to distinguish between leakage and defect current. Iddq testing of vlsi circuits frontiers in electronic. Introduction l iddq testing is the process of measuring iddq l iddq is the ieee symbol for the quiescent power supply current in an mos circuit. Builtin current sensors bics have been proposed both to speed up iddq testing and to increase its resolution by virtually partitioning the supply mesh, so that each partition has a relatively small defectfree iddq level 6. Therefore the spi communication doesnt work at vmicro only. Iddq testing is a cost effective test strategy for digital cmos ics with the voltage on the circuit s output pins andor iddq test. Cmos circuits based on the quiescent current supply iddq testing. Accurate macromodeling for leakage current for iddq test conference paper pdf available in conference record ieee instrumentation and measurement technology conference june 2007 with.
The effective ness of the test mode is demonstrated with a real life exam ple. Pdf analysis of issqiddq testing implementation and. The current consumed in the state is commonly called iddq for i dd quiescent, hence the name. Application note series i ddq testing of cmos ics test description this test involves measuring the current of the v dd power supply of a cmos ic when the inputs are at either v dd or v ss and the outputs are not connected. Application of iddq test in failure analysis of micro. All verilog, asic and systems designers, foundries, and ip developers. Iddq testing uses the principle that in a correctly operating quiescent cmos digital circuit, there is no static current path between the power supply and ground, except for a small amount of leakage. Basics of testing cmos electrical engineering news and.
It is little more than 15years since the idea of iddq testing was first proposed. Design for testability for soc based on iddq scanning miljana sokoloviu, predrag petkoviu, van. However, it is noticed that observing the average transient current can lead to improvements in real defect coverage, which is referred to iddt testing. An embodiment of a method includes applying a test pattern of inputs to a device, the device including one or more cmos complementary metaloxide semiconductor transistors, and obtaining current measurements for the device, each of the current measurements being a measurement of a current after applying an input of the test pattern to the device. Effective iddq testing method to identify the fault in low. Pdf accurate macromodeling for leakage current for iddq. For each of these tests, test results are presented to show the characteristics of each of several devices, implemented with di erent technologies.
Leakage current iddq test 56 is a defectbased test that measures device. Electric faults can be a major hazard and it can even lead to fatalities. Test system configuration figure 2 is a series 2600based system for testing the i ddq for cmos ics. Accurate macromodeling for leakage current for iddq test. Iddq testing is one of the many ways to test cmos integrated circuits in production. Aec q07 revb september 18, 2007 component technical committee automotive electronics council acknowledgment any document involving a complex technology brings together experience and skills from many sources.
Design for testability for soc based on iddq scanning. In one embodiment at least a portion of a semiconductor device is biased and a first quiescent current measurement is taken. This thesis presents test methods for characterization test, including contact test, input and output voltage level test, input leakage test, idd current test, power supply voltage bump test and iddq test by using the advantest t2000 test system. Number 2647 application note iddq testing and standby. Iddq testing does not guarantee detection, but works in practice because the floating output node is capacitively coupled to the substrate, as well. It has been recognized as the single most sensitive test method to detect cmos ic defects 3. Data with additional information from case studies is used to explain the effectiveness of iddq testing. To select from the available iddq test methods, the ones which most practically reduce test time. Iddq testing is a method for testing cmos integrated circuits for the presence of manufacturing. Vlsi testing, class assignments, course bulletin finals and grades. In our cases we are referring to iddq in cmos ics l perfect cmos circuits have iddq values typically less than 100 na there is no direct conducting path between vdd and vss. To show how a quiescent current supply test, iddq, contributes to ic defect isolation.
From the study, it is concluded that iddq testing is still applicable for the deep submicron vlsi for the next ten years. The major advantage of currentbased testing is that it does not. Edn iddq testing to improve yield and reliability, 12. Iddq testing of vlsi circuits frontiers in electronic testing. Voltage delta iddq testing on 1bit adder the iddq distribution for each fault for 1 bit adder is shown in figure 4,figure 5 and figure 6. A bipartite, differential iddq testable static rani design w. Dc parametric test and iddq test using advantest t2000 ate. The ac scan delay test uses scan chains to deliver vector pairs that verify timing behavior on specific paths path delay test or on identified gates or connections that are represented as faults transition delay test 4. Old view test was merely an afterthought specification design design errors fabrication testing random defects. Quiescent current analysis and experimentation of defective cmos circuits. Use a combination of manual, algorithmic, or atpg, generated test. As figure 2 shows, the hi and lo terminals of the 260x are connected to. The high leakages of the small process geometries question the. This paper describes the present status of iddq testing along with the essential items and necessary data related to iddq testing.
Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. The proposed iddq test method is first verified using 1bit adder in cadence, with nm ibm technology. Is iddq testing not applicable for deep submicron vlsi in. A novel defect detection technique using iddq data ashutosh sharma anura p. Low iddq pmic for battery energy harvesting applications. Iddq testing for cmos vlsi rochit rajsuman, senior member, ieee it is little more than 15years since the idea of iddq testing was first proposed. Also, a program to test the current drain of a cellular phone is available via keithleys web site. We are currently experiencing intermittent display of pdf links on some article pages.
Improved iddq testing with empirical linear prediction. Relative iddq testing and fault location for fpgas erik chmelar center for reliable computing stanford university december 1, 2003 c r c enter for eliable. Application note iddq testing and standby current testing. Many semiconductor companies now consider iddq testing as an integral part of the overall testing for all ics. These circuits are usually tested as a way to find different types of manufacturing faults. The current consumed in the state is commonly called iddq for idd quiescent and hence the name. The idea of this test is to measure drain current through the chip, while it is in the static state.
Iddq testing is a method for testing cmos integrated circuits for the presence of manufacturing faults. In order to solve the problem, this paper proposes a new micromodeling for leakage. Idt is an essential quality testing requirement for todays deep submicron devices dsm and very deep submicron devices vdsm. If a line is shorted to vdd, for example, it will still draw no extra current if the gate vsi the signal is attempting to set it to 1. Iddq testing uses the principle that in a correctly operating quiescent cmos digital circuitthere is no static current path between the power supply and ground, except for a small amount of leakage. Relative iddq do generate test configuration set used and unused interconnects test as applicationdependent fpga. If there are any internal shorts then higher icc current should indicate this. Iddq testing has progressed to become a worldwide accepted test method to detect cmos ic defects. This method relies on measuring the supply current idd in its. Iddq testing of vlsi circuits frontiers in electronic testing gulati, ravi k.
The portion of the semiconductor device that was biased is then unbiased and a second quiescent current measurement is taken. The iddq distribution for 1bit adder when the fault is at location 1. In this work, iddq current for deep submicron vlsi in year 2011 is estimated with a statistical approach according to the international technology roadmap for semiconductors 1999 edition considering process variations and. Controlling settle time in the iddq test program the test program must ensure the device and instruments are settled before making the current measurement. Iddq is listed in the worlds largest and most authoritative dictionary database of abbreviations and acronyms. Winner of the standing ovation award for best powerpoint templates from presentations magazine. The behavior of a cmos sram memory in the presence of open defects is analyzed.
Iddq testing for cmos vlsi proceedings of the ieee computer. Iddq testing idt is a novel approach for testing faults which are left undetected by voltage testing. Otherwise the measurement accuracy or variation may be larger than is acceptable. Iddq testing is a cost effective test strategy for digital cmos ics with the. By this definition, all cmos circuits are % iddq testable.
All irredundant single bfs in a circuit satisfying a1a6 can be detected using iddq testing. Quiescent current iddq testing has proven to be a very effective test screen for cmos circuits. For a circuit satisfying a1a6, a test detecting a single bf f also detects all multiple bfs that contain f. Normally a cmos logic consumes very little current in a static state. The application of reconfigurable neural networks off chip enables also good diagnostics capabilities. Iddq testing is sensitive to these these defects by simply monitoring the supply when cmos clock is stopped. To understand the challenges of the iddq measurement. Use table 5 for the proper jumper connection for vmicro only mode. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect.