Integrated circuit for detecting defects of through chip via
An integrated circuit that detects whether a through silicon via has defects or not, at a wafer level. The integrated circuit includes a semiconductor substrate, a through silicon via configured to be formed in the semiconductor substrate to extend to a certain depth from the surface of the semiconductor substrate, an output pad, and a current path providing unit configured to provide a current, flowing between the semiconductor substrate and the through silicon via, to the output pad during a test mode.
1. An integrated circuit comprising:
a semiconductor substrate;
a silicon via extending into the semiconductor substrate to a certain depth from the surface of the semiconductor substrate;
an output pad formed on the semiconductor substrate; and
a current path providing unit, formed in the semiconductor substrate, configured to establish a current path and provide a current, flowing from the semiconductor substrate and through the silicon via, to the output pad during a test mode,
wherein a first voltage is applied to a first well region of the semiconductor substrate during the test mode, the first voltage being greater than a schottky potential barrier formed at contact interface between a bottom of the silicon via and the semiconductor substrate.
2. The integrated circuit of claim 1 , wherein the first well region of the semiconductor substrate receives a ground voltage, during a normal mode.
3. The integrated circuit of claim 1 , wherein the current path providing unit is formed between the silicon via and the output pad, and is formed in a second well region, the second well region being doped by a second impurity different from a first impurity doping the first well region.
4. The integrated circuit of claim 3 , wherein the second well region receives a second voltage different from the first voltage to electrically separate the first well region and the second well region during the test mode.
5. The integrated circuit of claim 1 , further comprising an isolation layer configured to surround a sidewall portion of the silicon via, and isolate the silicon via from the semiconductor substrate.
6. The integrated circuit of claim 1 , wherein the current path providing unit comprises a MOS transistor having its source terminal electrically coupled to the silicon via and its drain electrically coupled to the output pad, the MOS transistor turning on or off in response to a test mode signal indicating whether the integrated circuit is in the test mode or not.
7. The integrated circuit of claim 6 , wherein the current path providing unit further comprises an input/output unit electrically coupled to the silicon via, the input/output unit configured to be enabled in a normal mode and disabled in the test mode.
8. The integrated circuit of claim 1 , further comprising:
a current forming unit suitable for forming a current that flows from the semiconductor substrate to the silicon via in response to a bias voltage.