Zaid's MSc Thesis

Published books and theses

Analysis of the Space of Functional
Fault Models and Its Application
to Embedded DRAMs

Type: Masters thesis
Date: October 1999
Author: Z. Al-Ars
Supervisor: Prof. Dr. Ir. A.J. van de Goor
Number of pages: 261
Technical Report number: 1-68340-28(1999)07
Order: please contact me by e-mail

Key words
Embedded DRAMs, circuit simulation, fault primitives, functional faults, functional tests

Abstract
Dynamic random access memories (DRAMs), the flagship products of the semiconductor industry, are among the devices worst affected by the imperfections in the production process of integrated circuits (ICs). This results in a costly, time consuming test procedure, the price of which is eventually payed by the end consumer. This report discusses the results of a study made to analyze the faulty behavior of the embedded DRAM devices produced by Siemens, Munich, Germany. The analysis is performed by injecting defects into an electrical model of the memory, then simulating it for possible faulty behavior. The results of the analysis can help produce more efficient test procedures for the studied memory.

Table of contents

Errata
A PostScript errata for the thesis can be downloaded here.

Analysis data
Row data files in text format for the fault analysis can be downloaded here. Each file name gives the name of the analyzed defect and the temperature of the analysis. For example, oc12.dat means that the file shows the fault analysis results for defect OC1 and at a temperature of 27 C. The file content itself is coded. The description of the code is outlined in the PostScript file here.

Below results for opens are given first, followed by shorts and bridges. All opens are analyzed at three temperatures: 27 C, 87 C, and 147 C. Shorts and bridges are analyzed at 27 C only.

OPENS
There are three types of opens: opens within cells (OC), opens on bit lines (OB), and opens in sense amplifiers (OS).

There are 4 opens within cells (OC):

Temp.	OC1	OC2	OC3	OC4
27 C	oc12	oc22	oc32	oc42
87 C	oc18	oc28	oc38	oc48
147 C	oc114	oc214	oc314	oc414

There 10 opens on bit lines (OB):

Temp.	OB1	OB2	OB3	OB4	OB5	OB6	OB7	OB8	OB9	OB10
27 C	ob12	ob22	ob32	ob42	ob52	ob62	ob72	ob82	ob92	ob02
87 C	ob18	ob28	ob38	ob48	ob58	ob68	ob78	ob88	ob98	ob08
147 C	ob114	ob214	ob314	ob414	ob514	ob614	ob714	ob814	ob914	ob014

There 8 opens in the sense amplifiers (OS):

Temp.	OS1	OS2	OS3	OS4	OS5	OS6	OS7	OS8
27 C	os12	os22	os32	os42	os52	os62	os72	os82
87 C	os18	os28	os38	os48	os58	os68	os78	os88
147 C	os114	os214	os314	os414	os514	os614	os714	os814

SHORTS
There are 10 shorts analyzed at 27 C, 5 of them are shorts to Vdd while the other 5 are shorts to GND. The results for these 10 shorts are given in the following table.

Short to	SC1	SC2	SB1	SB2	SS1
Vdd	sc1v	sc2v	sb1v	sb2v	ss1v
GND	sc1g	sc2g	sb1g	sb2g	ss1g

BRIDGES
There are 13 analyzed bridges, 5 of which are within cells (BWC) while the other 8 are between cells (BBC). The faulty behavior of many of these bridges is the same. Therefore, only one result file is given for defects with equivalent faulty behavior.

Bridges within cells	BWC1-2	BWC3-4
	bwc1	bwc3
Bridges between cells	BBC1-2	BBC3-6
	bbc1	bbc3