摘要:
A sputtering coil for a plasma chamber in a semiconductor fabrication system is provided. The sputtering coil couples energy into a plasma and also provides a source of sputtering material to be sputtered onto a workpiece from the coil to supplement material being sputtered from a target onto the workpiece. Alternatively a plurality of coils may be provided, one primarily for coupling energy into the plasma and the other primarily for providing a supplemental source of sputtering material to be sputtered on the workpiece.
摘要:
Embodiments of the present invention provide a method, article of manufacture, and apparatus for processing semiconductor wafers. The method includes preheating a semiconductor wafer in two types of chambers. In one embodiment, a first preheating chamber is a load lock and a second preheating chamber is a transition chamber. Semiconductor wafer processing systems which can perform embodiments of the method are presented.
摘要:
We disclose a method of applying a sculptured layer of material on a semiconductor feature surface using ion deposition sputtering, wherein a surface onto which the sculptured layer is applied is protected to resist erosion and contamination by impacting ions of a depositing layer, said method comprising the steps of a) applying a first portion of a sculptured layer with sufficiently low substrate bias that a surface onto which said sculptured layer is applied is not eroded away or contaminated in an amount which is harmful to said semiconductor device performance or longevity; and b) applying a subsequent portion of said sculptured layer with sufficiently high substrate bias to sculpture a shape from said the first portion, while depositing additional layer material. The method is particularly applicable to the sculpturing of barrier layers, wetting layers, and conductive layers upon semiconductor feature surfaces and is especially helpful when the conductive layer is copper. In the application of a barrier layer, a first portion of barrier layer material is deposited on the substrate surface using standard sputtering techniques or using an ion deposition plasma, but in combination with sufficiently low substrate bias voltage (including at no applied substrate voltage) that the surfaces impacted by ions are not sputtered in an amount which is harmful to device performance or longevity. Subsequently, a second portion of barrier material is applied using ion deposition sputtering at increased substrate bias voltage which causes resputtering (sculpturing) of the first portion of barrier layer material, while enabling a more anisotropic deposition of newly depositing material. A conductive material, and particularly a copper seed layer applied to the feature may be accomplished using the same sculpturing technique as that described above with reference to the barrier layer.
摘要:
A multi-step sputtering process in plasma sputter reactor having target and magnetron operable in two modes, for example, in a substrate sputter etch and a substrate sputter deposition. The target has an annular vault facing the wafer to be sputter coated. Various types of magnetic means positioned around the vault create a magnetic field supporting a plasma extending over a large volume of the vault. An integrated copper via filling process with the inventive reactor or other reactor includes a first step of highly ionized sputter deposition of copper, which can optionally be used to remove the barrier layer at the bottom of the via, a second step of more neutral, lower-energy sputter deposition of copper to complete the seed layer, and a third step of electroplating copper into the hole to complete the metallization. The first two steps can be also used with barrier metals.
摘要:
A deposition system in a semiconductor fabrication system provides at least one electron gun which injects energetic electrons into a semiconductor fabrication chamber to initiate and sustain a relatively high density plasma at extremely low pressures. In addition to ionizing atoms of the extremely low pressure gas, such as an argon gas at 100 microTorr, for example, the energetic electrons are also believed to collide with target material atoms sputtered from a target positioned above a substrate, thereby ionizing the target material atoms and losing energy as a result of the collisions. Preferably, the electrons are injected substantially tangentially to the walls of a chamber shield surrounding the plasma in a magnetic field generally parallel to a central axis of the semiconductor fabrication chamber connecting the target to and the substrate. As the injected electrons lose energy ionizing the target material atoms, the electrons spiral inward toward a central region of the semiconductor fabrication chamber surrounding the central axis, forming an electron cloud in the central region. An arrangement of electromagnets may be positioned adjacent the walls of the chamber shield surrounding the plasma to generate the magnetic field. It is believed that the configuration of magnetic fields also keeps electrons from colliding with the walls of the chamber shield surrounding the plasma.
摘要:
The present invention provides a method and apparatus for forming reliable interconnects in which the overlap of the line over the plug or via is minimized or eliminated. In one aspect, a barrier plug comprised of a conductive material, such as tungsten, is deposited over the via to provide an etch stop during line etching and to prevent diffusion of the metal, such as copper, into the surrounding dielectric material if the line is misaligned over the via. Additionally, the barrier plug prevents an overall reduction in resistance of the interconnect and enables reactive ion etching to be employed to form the metal line. In another aspect, reactive ion etching techniques are employed to selectively etch the metal line and the barrier layer to provide a controlled etching process which exhibits selectivity for the metal line, then the barrier and then the via or plug.
摘要:
A target and magnetron for a plasma sputter reactor. The target has an annular trough facing the wafer to be sputter coated. Various types of magnetic means positioned around the trough create a magnetic field supporting a plasma extending over a large volume of the trough. For example, the magnetic means may include magnets disposed on one side within a radially inner wall of the trough and on another side outside of a radially outer wall of the trough to create a magnetic field extending across the trough, to thereby support a high-density plasma extending from the top to the bottom of the trough. The large plasma volume increases the probability that the sputtered metal atoms will become ionized. The magnetic means may include a magnetic coil, may include additional magnets in back of the trough top wall to increase sputtering there, and may include confinement magnets near the bottom of the trough sidewalls. The magnets in back of the top wall may have an outer magnet surrounding an inner magnet of the opposite polarity. The high aspect ratio of the trough also reduces asymmetry in coating the sidewalls of a deep hole at the edge of the wafer. An integrated copper via filling process includes a first step of highly ionized sputter deposition of copper, a second step of more neutral, lower-energy sputter deposition of copper to complete the seed layer, and electroplating copper into the hole to complete the metallization.
摘要:
A process for fabricating metal plugs, such as aluminum plugs, in a semiconductor workpiece. The invention is suitable for filling narrow, high aspect ratio holes, and the invention minimizes the formation of TiAl3 or other products of interdiffusion between the plug and the wetting layer. First, an optional barrier layer is created by covering the bottom of a hole with a film containing titanium nitride doped with silicon. Second, a wetting layer is created by covering the side walls of a hole with a film containing titanium doped with silicon, in a Ti:Si molar ratio greater than 1:2. Preferably, the wetting layer is created by sputter deposition using a titanium sputtering target containing 0.1% to 20% wt silicon, most preferably 5% to 10% wt silicon. Third, the hole is filled by depositing a material consisting primarily of aluminum. The hole preferably is filled by sputter deposition using an aluminum sputtering target, optionally containing dopants such as copper. To facilitate filling the hole without voids, the aluminum sputter deposition preferably is performed “warm”, i.e., with the workpiece at a temperature below the melting point of aluminum but high enough to promote reflow of the deposited material. The silicon atoms in the wetting layer inhibit the titanium from reacting with the aluminum, and the wetting layer facilitates filling the hole with the aluminum material without leaving unfilled voids.
摘要:
An aluminum sputtering process, particularly useful for filling vias and contacts of high aspect ratios formed through a dielectric layer and also usefull for forming interconnects that are highly resistant to electromigration. A liner or barrier layer is first deposited by a high-density plasma (HDP) physical vapor deposition (PVD, also called sputtering) process, such as is done with an inductively coupled plasma. If a contact is connected at its bottom to a silicon element, the first sublayer of the liner layer is a Ti layer, which is silicided to the silicon substrate. The second sublayer comprises TiN, which not only acts as a barrier against the migration of undesirable components into the underlying silicon but also when deposited with an HDP process and biased wafer forms a dense, smooth crystal structure. The third sublayer comprises Ti and preferably is graded from TiN to Ti. Over the liner layer, an aluminum layer is deposited in a standard, non-HDP process. The liner layer allows the hottest part of the aluminum deposition to be performed at a relatively low temperature between 320 and 500° C., preferably between 350 and 420° C., while still filling narrow plug holes, and the TiN does not need to be annealed to form an effective barrier against diffusion into the silicon. A horizontal interconnect formed by the inventive process is resistant to electromigration.