Techniques for determining a fault probability of a location on a chip

1. A method for determining a fault probability of a location on a chip, comprising:

applying, using a computer, a number of tests at a number of input nodes of a circuit chip, wherein each test defines for each input node a test input choice;

measuring for each test a signal at each of a number of measurement nodes to acquire for each measurement node a number of measurement values, wherein each measurement value is associated to the test it was measured for and to the measurement node it was measured at;

determining relevance values for detection of a fault on the circuit chip, wherein each relevance value is calculated based on a correlation between normalized test input choices and normalized measurement values associated to the test it was measured for and to the measurement node it was measured at, each relevance value representing a relevance of a combination of an input node of a first number of input nodes with a measurement node of a second number of measurement nodes for detection of a fault on a chip,

determining for each signal path of a fourth number of signal paths of the chip, a distance from a location to each of the fourth number of signal paths of the chip, wherein each signal path extends from an input node of the first number of input nodes to a measurement node of the second number of measurement nodes; and

determining the fault probability based on adding the distances to each of the fourth number of paths weighted by the relevance value of the combination of the input node the respective path extends from, and the measurement node the respective path extends to.

2. The method according to claim 1 , wherein the fault probability F(x,y,z) is determined as follows:

F

⁡

(

x

,

y

,

z

)

=

∑

i

=

1

I

⁢

∑

m

=

1

M

⁢

∑

p

=

1

P

⁡

(

i

,

m

)

⁢

R

⁡

(

i

,

m

)

/

P

⁡

(

i

,

m

)

1

+

L

⁡

(

(

x

,

y

,

z

)

,

i

,

m

,

p

)

/

L

0

wherein (x,y,z) is the location, wherein i is the index of the input nodes with i =1 . . . I, m is the index for the measurement nodes with m =1 . . . M, wherein P(i,m) is a number of paths from input node i to measurement node m, wherein R(i,m) is the relevance value of the combination (i,m) of an input node i with a measurement node m, wherein L((x,y,z),i,m,p) is the distance from location (x,y,z) to the p-th path from input node i to measurement m, and wherein L 0 is the half-decay length defining the location resolution.

3. The method according to claim 1 , further comprising:

providing position information for each input node and each measurement node and defining a path of the fourth number of paths as a straight line between the position of the input node and the position of the measurement node.

4. The method according to claim 1 , further comprising:

providing a position information for each input node and each measurement node, and providing for a path of the fourth number of paths a plurality of further nodes to define the position of the path between the position of the input node and the position of the measurement node.

5. The method according to claim 1 , further comprising:

correlating the fault probability with a position indicator, the position indicator comprising different values for locations of the chip, where input nodes, measurement nodes or signal paths are positioned compared to locations, where none of these are positioned.

6. The method according to claim 1 , further comprising:

determining the fault probability of a plurality of locations on a chip to acquire a fault probability distribution with regard to the plurality of fault probabilities.