Methods of forming through via
A through via process is performed on a semiconductor substrate with a contact plug formed in an interlayer dielectric (ILD), and then a via plug is formed in the ILD layer to extend through a portion of the semiconductor substrate, followed forming an interconnection structure electrically connected with the contact plug and the via plug.
1. A through via process, comprising:
providing a semiconductor substrate, comprising: an integrated circuit (IC) component formed on said semiconductor substrate; an interlayer dielectric (ILD) layer formed on said semiconductor substrate and covering said IC component, and a contact plug formed in said ILD layer and electrically connected to said IC component;
forming at least one via hole subsequent to the contact plug formation, said via hole extending through said ILD layer and a portion of said semiconductor substrate;
depositing a passivation layer lining the bottom and sidewalls of said via hole;
after depositing said passivation layer, depositing a conductive material layer on said ILD layer to fill said via hole;
removing said conductive material layer outside the via hole to expose said conductive material layer and the top of said contact plug, wherein said conductive material layer remaining in said via hole forms a via plug;
removing a portion of the passivation layer after the conductive material layer is deposited; and
after removing the portion of the passivation layer, forming an interconnection structure comprising a plurality of metal layers formed in a plurality of inter-metal dielectric (IMD) layers, wherein a lowermost metal layer of said interconnection structure is electrically connected to the exposed portions of said contact plug and said via plug.
2. The through via process of claim 1 , wherein said conductive material layer comprises copper or copper-based alloy.
3. The through via process of claim 1 , wherein said contact plug is formed of tungsten or tungsten-based alloy.
4. The through via process of claim 1 , where said passivation layer comprises silicon oxide, silicon nitride, or combinations thereof.
5. A method, comprising:
providing a first wafer, comprising: a first semiconductor substrate; a first integrated circuit (IC) component formed on said first semiconductor substrate; and an interlayer dielectric (ILD) layer formed on said semiconductor substrate and covering said IC component;
successively forming a contact plug and a via plug subsequent to said formation of said contact plug in said ILD layer, wherein said contact plug is electrically connected to said IC component, and said via plug extends through a portion of said first semiconductor substrate, wherein forming the via plug comprises:
depositing a passivation layer lining the bottom and sidewalls of a via hole corresponding to said via plug;
after depositing said passivation layer, depositing a conductive material layer on said ILD layer to fill said via hole;
removing said conductive material layer outside the via hole to expose said conductive material layer and the top of said contact plug, wherein said conductive material layer remaining in said via hole forms said via plug;
removing a portion of the passivation layer after the conductive material layer is deposited;
after removing the portion of the passivation layer, forming an interconnection structure on said ILD layer, wherein said interconnection structure is electrically connected to said contact plug and said via plug respectively;
providing a second wafer; and
bonding said first wafer to said second wafer to form a wafer stack.
6. The method of claim 5 , wherein said via plug comprises copper or copper-based alloy.
7. The method of claim 5 , wherein said contact plug is formed of tungsten or tungsten-based alloy.
8. The method of claim 5 , where said passivation layer comprises silicon oxide, silicon nitride, or combinations thereof.
9. A through via process, comprising:
providing a semiconductor substrate, comprising: an integrated circuit (IC) component formed on said semiconductor substrate; an interlayer dielectric (ILD) layer formed on said semiconductor substrate and covering said IC component, and a contact plug formed in said ILD layer and electrically connected to said IC component;
forming at least one via hole extending through said ILD layer and a portion of said semiconductor substrate;
depositing a passivation layer lining the bottom and sidewalls of said via hole;
after depositing said passivation layer, depositing a conductive material layer on said ILD layer to fill said via hole;
forming a via plug by removing said conductive material layer outside the via hole to expose said conductive material layer and the top of said contact plug;
removing a portion of the passivation layer after the conductive material layer is deposited; and
after removing the portion of the passivation layer, forming an interconnection structure comprising a plurality of metal layers formed in a plurality of inter-metal dielectric (IMD) layers, wherein a lowermost metal layer of said interconnection structure is electrically connected to the exposed portions of said contact plug and said via plug.