REFRACTORY METAL CAPPED LOW RESISTIVITY METAL CONDUCTOR LINES AND VIAS USING PVD AND CVD

    公开(公告)号:SG115407A1

    公开(公告)日:2005-10-28

    申请号:SG200105658

    申请日:1993-02-01

    Applicant: IBM

    Abstract: Capping a low resistivity metal conductor line or via with a refractory metal allows for effectively using chemical-mechanical polishing techniques because the hard, reduced wear, properties of the refractory metal do not scratch, corrode, or smear during chemical-mechanical polishing. Superior conductive lines and vias are created using a combination of both physical vapor deposition (e.g., evaporation or collimated sputtering) of a low resistivity metal or alloy followed by chemical vapor deposition (CVD) of a refractory metal and subsequent planarization. Altering a ratio of SiH 4 to WF 6 during application of the refractory metal cap by CVD allows for controlled incorporation of silicon into the tungsten capping layer. Collimated sputtering allows for creating a refractory metal liner in an opening in a dielectric which is suitable as a diffusion barrier to copper based metallizations as well as CVD tungsten. Ideally, for faster diffusing metals like copper, liners are created by a two step collimated sputtering process wherein a first layer is deposited under relatively low vacuum pressure where directional deposition dominates (e.g., below 1mTorr) and a second layer is deposited under relatively high vacuum pressure where scattering deposition dominates (e.g., above 1mTorr). For refractory metals like CVD tungsten, the liner can be created in one step using collimated sputtering at higher vacuum pressures.

    CHARGE PUMP SYSTEM HAVING MULTIPLE INDEPENDENTLY ACTIVATED CHARGE PUMPS AND CORRESPONDING METHOD

    公开(公告)号:SG90212A1

    公开(公告)日:2002-07-23

    申请号:SG200007131

    申请日:2000-12-04

    Abstract: A charge pump generator system and method is provided which more precisely maintains the level of an internally generated voltage supply by operating some or all of the available charge pumps depending upon the voltage level reached by the voltage supply. When the voltage supply is far from its target level, a first group and a second group of charge pumps are operated. The first group may preferably have a faster pumping rate or a greater number of charge pumps than the second group. When the voltage supply exceeds a first predetermined level, the first group of charge pumps is switched off while the second group remains on, such that the rate of charge transfer slows. The second group continues operating until a second, e.g. target, voltage level is exceeded. The slower rate of charge transfer then effective reduces overshoot, ringing and noise coupled onto the voltage supply line. Preferably, at least one charge pump operates in both standby and active modes, thereby reducing chip area.

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