Abstract: Test structures for wafers are disclosed. A device may include a silicon wafer including a number of die and a scribe area between two die of the number of die. The scribe area may include one or more test structures. The test structures may include a p-doped region and an n-doped region adjacent to the p-doped region. The test structures may also include a first contact electrically coupled to the p-doped region and a second contact electrically coupled to the n-doped region. The second contact may be proximate to the first contact. Associated devices, systems, and methods are also disclosed.