Table 1295. Shallow trench isolation (STI) failure mechanisms of CMOS.
STI |
Test polarity |
Pin pair (stress/reference) |
Failure mechanism |
Failure location |
[1] |
N+ diffusion diodes |
Positive |
VSS |
Silicide penetration, metallurgical junction, contacts |
Junction surface, Metallurgical junction edge, contact-to-silicon surface |
[1] |
P+ diffusion diedes |
Positive |
VDD |
Silicon melting, TiSi2 salicide resistance, CoSi2 agglomeration, contact |
N-well under shallow tranch isolation, silicide surface |
[1] |
N-well diodes |
Negative |
VSS |
Metallurgical junction failure |
|
[1] |
N-well to n-well |
Negative |
Well-to-well |
Molten silicon |
Shallow trench isolation between wells |
[1] |
N-channel MOSFET |
Positive |
Drain-to-source |
MOSFET second breakdown |
Molten silicon, MOSFET channel region |
[1] |
Positive |
Gate |
Gate dielectric failure |
MOSFET gate |
[1] |
P-channel MOSFET |
Negative |
Drain-to-source |
MOSFET second breakdown |
Molten silicon, MOSFET channel region |
[1] |
Negative
|
MOSFET gate |
Gate dielectric failure |
MOSFET gate |
[1] |
N-well resistors |
|
|
Resistor second breakdown |
Resistor metallurgical junction, contacts |
[1] |
N-well ballasted |
Positive |
Drain-to-source |
MOSFET second breakdown |
Molten silicon |
[1] |
N-channel MOSFET |
Positive
|
Gate |
Gate dielectric failure |
MOSFET channel region and gate |
[1] |
Aluminum wire interconnect |
Positive |
|
Aluminum melting |
Aluminum film |
[1] |
Negative |
|
Dielectric cracking |
Aluminum-ILD interface |
[1] |
Tungsten first level |
Positive |
Signal pin |
ILD (inter-layer-dielectric) breakdown |
Tungsten film-to-polysilicon fill shape, ILD |
[1] |
Tungsten stud contact |
|
|
Tungsten melting |
Tungsten film, silicon surface |
[1] |
Tungsten stud bar contact |
Positive |
|
Tungsten melting |
Tungsten film |
[1] |
Negative |
|
|
Silicon surface |
[1] |
Copper interconnect |
Positive |
|
Copper melting |
Copper film |
[1] |
Negative |
|
Dielectric cracking |
Cracking at the Cu-ILD top surface |
[1] |
Copper via |
Positive |
|
Copper melting |
Copper film |
[1] |
Negative |
|
|
Cracking at the Cu-ILD top surface |
[1] |
Copper dual damascene |
Positive |
|
Copper film and via |
Displacement of Cu film and via |
[1] |