Sputtered Films, Inc.

Andrew P Clarke

Peter J Clarke

An electrical field between a positive anode and a negative target in a cavity and a magnetic field in the cavity cause electrons from the target to ionize neutral gas (e.g. argon) atoms in the cavity. The ions cause the target to release sputtered atoms (e.g. aluminum) for deposition on a substrate. A shield between the target and the substrate inhibits charged particle movement to the substrate. The anode potential may be positive, and the shield and the magnetic members may be grounded, to obtain electron movement to the anode, thereby inhibiting the heating of the shield and the magnetic members by electron impingement. The anode may be water cooled. The magnitude of the positive anode voltage relative to the target voltage provides selectively for (a) a uniform thickness of sputtered atoms on the walls of a groove in the substrate or (b) a filling of the groove by the sputtered atoms and a uniform thickness of deposition on the substrate surface including the filled groove. Progressive differences in the anode-substrate voltage produce progressive increases in the rate of the sputtered atom deposition on the substrate. Oxygen flow into the cavity may be varied through a wide range at a substantially constant anode voltage to produce a deposition of aluminum oxide on the substrate with variations in the refraction index between approximately 1.63-1.70. A selected oxygen flow rate may accordingly produce an acceptable aluminum oxide refraction index in the 1.63-1.70 range, without affecting the anode voltage, even with minor oxygen flow rate variations.

Apparatus for, and method of, depositing a film on a substrate

A conductive adhesion layer (e.g. titanium 150 .ANG. thick) is formed on a substrate. A first conductive barrier layer (e.g. high-density gold-colored titanium-nitride 300 .ANG. thick) having properties of microcracking in a first direction to relieve inherent stress is deposited on the conductive adhesion layer. A second conductive barrier layer (e.g. low-density brown-colored titanium-nitride 400 .ANG. thick) having properties of low inherent stress is deposited on the first barrier layer. The second barrier layer may be exposed to air, thereby further inhibiting the leakage to the substrate of material from a conductive layer (e.g. aluminum silicon copper or aluminum copper) when a third barrier layer (e.g. high-density gold-colored titanium nitride 300 .ANG. thick) and such conductive layer are thereafter sequentially deposited on the second barrier layer. Such method may be used to provide a substantially uniform deposition on the walls of a groove for receiving a via. An insulating coating (e.g. silicon dioxide) may be deposited on the substrate and this coating may be etched to define the groove. The conductive layer and the first and second barrier layers may then be formed on the groove walls and the second layer may be exposed to air. The second barrier layer may then be etched as by argon to redistribute the second barrier layer into a substantially uniform thickness on the groove walls. The third barrier layer and the conductive layer may then be sequentially deposited on the second barrier layer in the groove.

Method of depositing materials on a wafer to eliminate the effect of

An electrical field between a positive anode and a negative target in a cavity and a magnetic field in the cavity cause electrons from the target to ionize neutral gas (e.g. argon) atoms in the cavity. The ions cause the target to release sputtered atoms (e.g. aluminum) for deposition on a substrate. A shield between the target and the substrate inhibits charged particle movement to the substrate. The anode potential may be positive, and the shield and the magnetic members may be negative relative to the anode, to obtain electron movement to the anode, thereby inhibiting the heating of the shield and the magnetic members by electron impingement. The anode may be water cooled. The magnitude of the positive anode voltage relative to the target voltage provides selectively for (a) a uniform thickness of sputtered atoms on the walls of a groove in the substrate or (b) a filling of the groove by the sputtered atoms and a uniform thickness of deposition on the substrate surface including the filled groove. Progressive increases in the anode voltage produce progressive increases in the rate of the sputtered atom deposition on the substrate. A sensor may receive infra red energy passing from the substrate through a hole in the anode to provide signals having characteristics indicating variations in the substrate temperature. The anode voltage is varied in accordance with the characteristics of such signal to regulate the temperature of the substrate. The target voltage is preferably varied with the anode voltage variations to maintain the anode-cathode voltage difference substantially a constant.

A target releases electrons to an anode through a cavity containing gaseous atoms (e.g. argon) having properties of becoming ionized by electron impingement. Magnetic and electrical fields increase the distance of electron travel between the anode and the target, thereby enhancing ion formation from the gaseous atoms. The ions bombard the target and cause it to emit sputtered atoms (e.g. aluminum) which are deposited on a substrate (e.g. wafer) displaced from the target. In one embodiment, a shield disposed between the target and the substrate is shaped, and has a potential, to attract charged particles and prevent them from moving to the substrate. This allows the wafer to be disposed close to the target, thereby enhancing the density, and the thickness uniformity, of the deposition on the substrate. The shield also acts as a getter to remove impurities (e.g. water molecules) from the space between the target and the substrate. In another embodiment the shield has a positive potential to attract electrons and repel ions, thereby funneling ions toward the substrate. The funnel shape is dependent upon the shield voltage. A hood displaced slightly (e.g. 50 mils) from the shield is shaped, and has a potential (e.g. ground), to attract charged particles near the hood and outside of the funnel. The funneled ions and sputtered atoms are deposited on the substrate to generate heat in the substrate, thereby enhancing the properties of the substrate deposition. Sputtered atoms between the shield and the hood form a dielectric to prevent any voltage breakdown between the shield and the hood.

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Carpinteria, CA, United States of America

Andrew P Clarke