Semiconductor wafer including cracking stopper structure and method of forming the same
View Patent ↗A semiconductor wafer may include, but is not limited to, the following elements. A semiconductor substrate has a device region and a dicing region. A stack of inter-layer insulators may extend over the device region and the dicing region. Multi-level interconnections may be disposed in the stack of inter-layer insulators. The multi-level interconnections may extend in the device region. An electrode layer may be disposed over the stack of inter-layer insulators. The electrode layer may extend in the device region. The electrode layer may cover the multi-level interconnections. A cracking stopper groove may be disposed in the dicing region. The cracking stopper groove may be positioned outside the device region.
1. A method of forming a semiconductor device, the method comprising:
forming a stack of inter-layer insulators extending over a device region and a dicing region of a semiconductor substrate;
forming first and second multi-level interconnection structures in the stack of inter-layer insulators, the first multi-level interconnection structure being positioned in the device region, the second multi-level interconnection structure being positioned in the dicing region;
forming an electrode layer over the stack of inter-layer insulators formed; and
removing the second multi-level interconnection structure by carrying out a selective wet etching process using the electrode layer as a mask to etch the second multi-level interconnection structure, thereby forming the cracking stopper groove in the dicing region while leaving the first multi-level interconnection structure in the device region.
2. The method according to claim 1 , wherein the electrode layer comprises a first material, and the second multi-level interconnection structures comprises a second material, and
the wet etching process is carried out using an etchant that dissolves the second material and does not dissolve the first material.
3. The method according to claim 1 , wherein the first and second multi-level interconnection structures are formed by a damascene method.
4. The method according to claim 1 , wherein at least one of the inter-layer insulators other than the upper most inter-layer insulator has a dielectric constant of less than 3.9.
5. The method according to claim 1 , wherein the cracking stopper groove surrounds the device region and the cracking stopper groove is surrounded by a dicing line of the semiconductor wafer.
6. The method according to claim 1 , wherein the first and second multi-level interconnection structures comprise adjacent structures on the device, and are separated only by materials of the stack of inter-layer insulators.
7. The method according to claim 1 , further comprising forming a passivation layer on a surface and side walls of the electrode layer.
8. The method according to claim 1 , further comprising using at least a portion of the electrode layer as a test terminal and a bonding pad.
9. The method according to claim 1 , further comprising:
forming a passivation layer over the electrode layer; and
selectively providing an opening in the passivation layer to permit the electrode layer to serve as a test terminal and a bonding pad.
10. The method according to claim 2 , wherein the first material is Al and the second material is Cu, and the etchant is a nitric acid.
11. The method according to claim 7 , further comprising dicing said device from a wafer used to fabricate said device.