1. Field of the Invention
An embodiment of the present invention relates to microelectronic device fabrication. In particular, an embodiment of the present invention relates to a tantalum containing adhesion layer for metal contacts deposited by atomic layer deposition to minimize contact resistance and maximize the low resistance conductive material within the contact.
2. State of the Art
The microelectronic device industry continues to see tremendous advances in technologies that permit increased integrated circuit density and complexity, and equally dramatic decreases in power consumption and package sizes. Present semiconductor technology now permits single-chip microprocessors with many millions of transistors, operating at speeds of tens (or even hundreds) of MIPS (millions of instructions per second), to be packaged in relatively small, air-cooled microelectronic device packages. These transistors are generally connected to one another or to devices external to the microelectronic device by conductive traces and contacts through which electronic signals are sent and/or received.
One process used to form contacts is known as a “damascene process”. In a typical damascene, a photoresist material is patterned on a dielectric material and the dielectric material is etched through the photoresist material patterning to form a hole extending to a source or drain of an underlying transistor. The photoresist material is then removed (typically by an oxygen plasma) and an adhesion layer may be deposit within the hole to prevent delimination between the dielelctric material and a subsequently deposited conductive material. The hole is then filled, usually by deposition, with the conductive material (e.g., such as metal and metal alloys thereof). For example, a 60-90 angstrom thick titanium nitride adhesion layer may be deposited in about a 70-80 nm diameter hole (65 nm technology node) by chemical vapor deposition followed by the filling of the remainder of the hole with tungsten. The adhesion layer may also prevent damage to the dielectric material during the deposition of the conductive material. For example, a titanium nitride adhesion layer prevents damage to the dielectric layer (such as silicon dioxide) by a tungsten hexafluoride gas used to deposit tungsten, as will be understood to those skilled in the art. The resulting structure is planarized, usually by a technique called chemical mechanical polish (CMP), which removes the conductive material and adhesion layer that is not within the hole from the surface of the dielectric material, to form the contact.
It is, of course, understood that since the adhesion layer has a higher electrical resistance than the conductive material, the conductive material must have a sufficient cross-sectional area within the contact to effectively conduct signals. However, as transistors become smaller with each successive technology node, the contact geometries decrease (i.e., “scale down”). Thus, a 60-90 angstrom thick adhesion layer, discussed above, will become problematical. For example, at the 45 nm technology node, the contact geometry (i.e., width) will be about 60 nm. Thus, a 90 angstrom thick adhesion layer will occupy about 30% of the contact width. As a further example, at the 30 nm technology node, the contact geometry will be about 40 nm. Thus, a 90 angstrom thick adhesion layer will occupy about 45% of the contact width. With both of these examples, it will be clear to those skilled in the art that the remaining contact width will likely not yield a cross-sectional area of the conductive material within the contact that will be sufficient to effectively conduct a reliable signal.
Therefore, it would be advantageous to develop apparatus and techniques to form an adhesion layer which will allow effective scaling down of contacts, as transistors become smaller with each successive technology node.
While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings to which:
In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein, in connection with one embodiment, may be implemented within other embodiments without departing from the spirit and scope of the invention. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, appropriately interpreted, along with the full range of equivalents to which the claims are entitled. In the drawings, like numerals refer to the same or similar functionality throughout the several views.
The second active area 104 includes a second transistor 142 comprising a source region 144 and a drain region 146 implanted into a microelectronic substrate 108. A gate 152 is positioned between the second transistor source region 144 and the second transistor drain region 146. The second transistor gate 152 comprises a gate dielectric 154, a gate electrode 156, a gate cap 158, and gate spacers 162 and 162′, as will be understood by those skilled in the art.
A first dielectric layer 164, such as silicon dioxide, carbon doped oxide, and the like, is deposited over the first transistor gate 122, the first transistor source region 114, the first transistor drain region 116, the second transistor gate 142, the second transistor source region 144, and the second transistor drain region 146. A second dielectric layer 166, such as silicon dioxide, carbon doped oxide, and the like, may be deposited over the first dielectric layer 164.
As shown in
As shown in
As shown in
As shown in
The described embodiment can result in a reduction in the resistivity of the overall contact by increasing the percent of the contact structure that is filled with the conductive metal. Furthermore, as the formation of the atomic layer disposed tantalum containing adhesion layer 176 and the deposition of the conductive material 178 can be carried out in a common chemical vapor deposition chamber, there is the ability to integrate the two processes into one tool to reduce process flow complexity and reduce overall fabrication processing costs for the contacts 180 and 180′.
It has been experimentally shown that a 10 angstrom atomic layer deposited tantalum containing layer can reduce the contact resistance of a 65 nm technology node copper contact by over 60% compared to an approximate 130 angstrom physical vapor deposited tantalum containing layer. The chemical composition of the tantalum containing layer may contain about 10% oxygen, about 25% carbon with the remainder tantalum and nitrogen (collectively “TaN” described below)
It is, of course, understood that the present invention can be practiced with a variety of structures and configurations, such as a through a single dielectric layer 182 as shown in
The packages formed with the adhesion layer of the present invention may be used in a hand-held device 210, such as a cell phone or a personal data assistant (PDA), as shown in
The microelectronic device assemblies formed with the adhesion layer of the present invention may also be used in a computer system 310, as shown in
Having thus described in detail embodiments of the present invention, it is understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations thereof are possible without departing from the spirit or scope thereof.
Number | Name | Date | Kind |
---|---|---|---|
6153519 | Jain et al. | Nov 2000 | A |
6204204 | Paranjpe et al. | Mar 2001 | B1 |
6229211 | Kawanoue et al. | May 2001 | B1 |
6627995 | Paranjpe et al. | Sep 2003 | B2 |
6706626 | Huang | Mar 2004 | B2 |
6794284 | Vaartstra | Sep 2004 | B2 |
6838125 | Chung et al. | Jan 2005 | B2 |
6846516 | Yang et al. | Jan 2005 | B2 |
6951804 | Seutter et al. | Oct 2005 | B2 |
6960675 | Chen et al. | Nov 2005 | B2 |
6972267 | Cao et al. | Dec 2005 | B2 |
7049226 | Chung et al. | May 2006 | B2 |
7071562 | Ngo et al. | Jul 2006 | B2 |
7081271 | Chung et al. | Jul 2006 | B2 |
7198815 | Chen et al. | Apr 2007 | B2 |
7276441 | Cui et al. | Oct 2007 | B1 |
7314835 | Ishizaka et al. | Jan 2008 | B2 |
7341959 | Brcka | Mar 2008 | B2 |
7371878 | Chen et al. | May 2008 | B2 |
7407881 | Lee | Aug 2008 | B2 |
7425506 | Kailasam | Sep 2008 | B1 |
7435454 | Brcka | Oct 2008 | B2 |
7446032 | Kailasam | Nov 2008 | B2 |
7482286 | Misra et al. | Jan 2009 | B2 |
7521356 | Ramaswamy et al. | Apr 2009 | B2 |
20020058163 | Uzoh et al. | May 2002 | A1 |
20020106846 | Seutter et al. | Aug 2002 | A1 |
20030057526 | Chung et al. | Mar 2003 | A1 |
20030057527 | Chung et al. | Mar 2003 | A1 |
20030059538 | Chung et al. | Mar 2003 | A1 |
20030060042 | Park et al. | Mar 2003 | A1 |
20030082301 | Chen et al. | May 2003 | A1 |
20030124262 | Chen et al. | Jul 2003 | A1 |
20030219979 | Choi et al. | Nov 2003 | A1 |
20030224600 | Cao et al. | Dec 2003 | A1 |
20040048461 | Chen et al. | Mar 2004 | A1 |
20040077183 | Chung | Apr 2004 | A1 |
20040187304 | Chen et al. | Sep 2004 | A1 |
20040219369 | Garg et al. | Nov 2004 | A1 |
20040234704 | Garg et al. | Nov 2004 | A1 |
20040241321 | Ganguli et al. | Dec 2004 | A1 |
20040262658 | Rasmussen | Dec 2004 | A1 |
20050009325 | Chung et al. | Jan 2005 | A1 |
20050037557 | Doczy et al. | Feb 2005 | A1 |
20050124154 | Park et al. | Jun 2005 | A1 |
20050272247 | Ikeda et al. | Dec 2005 | A1 |
20060006542 | Lee | Jan 2006 | A1 |
20060030148 | Seutter et al. | Feb 2006 | A1 |
20060084266 | Narushima et al. | Apr 2006 | A1 |
20060102895 | Hendrix et al. | May 2006 | A1 |
20060121307 | Matsuzawa et al. | Jun 2006 | A1 |
20060213437 | Ishizaka et al. | Sep 2006 | A1 |
20060225655 | Faguet et al. | Oct 2006 | A1 |
20070042577 | Ishizaka | Feb 2007 | A1 |
20080102205 | Barry et al. | May 2008 | A1 |
20080299782 | Ramaswamy et al. | Dec 2008 | A9 |
20090043119 | Sekimoto et al. | Feb 2009 | A1 |
20090045514 | Ishizaka et al. | Feb 2009 | A1 |
20090163025 | Humayun et al. | Jun 2009 | A1 |
Number | Date | Country |
---|---|---|
1134757 | Oct 1996 | CN |
WO 03038892 | May 2003 | WO |
WO 03038892 | May 2003 | WO |
Number | Date | Country | |
---|---|---|---|
20060003581 A1 | Jan 2006 | US |