Test line placement to improve die sawing quality

A semiconductor wafer structure comprising:

• a die region extending from a bottom surface to a top surface of the semiconductor wafer;
• a scribe line region adjacent the die region and extending from the bottom surface of the semiconductor wafer to the top surface of the semiconductor wafer;
• test devices in the scribe line region;
• a plurality of test pads in the scribe line region and in a plurality of dielectric layers, wherein the test pads in a top dielectric layer are connected to the test devices and underlying test pads in the dielectric layers, and wherein the test pads form test lines in respective dielectric layers;
• and
• a free region substantially in an intersection region of the scribe line region and an additional scribe line region perpendicular to the scribe line region, wherein at least one of the test lines crosses the intersection region, and wherein test pads are formed outside the free region.

A semiconductor wafer structure comprising:

• a first scribe line extending along a first direction and adjacent a die;
• a first maximum kerf region in the first scribe line;
• a second scribe line extending along a second direction adjacent the die, wherein the first and the second scribe lines have an intersection region;
• a second maximum kerf region in the second scribe line;
• a test line in the first scribe line, wherein the test line crosses the intersection region;
• a free region defined by an overlap region of the first and the second maximum kerf regions;
• and
• test pads in the test line and only outside the free region.

A method of fabricating a semiconductor structure, the method comprising:

• providing a semiconductor wafer having a first scribe line and a second scribe line;
• reserving a location for a test line, wherein the location is in the first scribe line and crosses an intersection area of the first scribe line and the second scribe line;
• defining a free region in the intersection area, wherein a probability of kerf lines being outside the free region is substantially low;
• forming test pads in the location, wherein two of the test pads are placed on opposite sides of the free region, and the free region is free from test pads;
• sawing through the first scribe line;
• and
• sawing through the second scribe line to separate dies.