Semiconductor device and method for manufacturing the same
AssigneeFujitsu Limited
InventorWensheng WANG
Life of this patent
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Abstract
According to one embodiment, after forming transistors on a semiconductor substrate, a stopper layer and an interlayer insulating film are formed. Then, a contact hole is formed in the interlayer insulating film and a copper film is formed on the interlayer insulating film to bury the inside of the contact hole with copper. After that, the copper film on the interlayer insulating film is removed by low-pressure CMP polishing or ECMP polishing to planarize a surface thereof to form plugs. Thereafter, a barrier metal, a lower electrode, a ferroelectric film, and an upper electrode are formed. In this manner, a semiconductor device (FeRAM) having a ferroelectric capacitor is formed.
Claims20
A semiconductor device, comprising:
- a semiconductor substrate;
- an impurity region formed by introducing impurities into the semiconductor substrate;
- an interlayer insulating film formed over the semiconductor substrate;
- a conductive plug formed through the interlayer insulating film;
- and
- a capacitor provided over the conductive capacitor,
- wherein the capacitor includes a lower electrode, which is electrically connected to the impurity region through the conductive plug, a dielectric film made of a ferroelectric or a high dielectric on the lower electrode, and an upper electrode on the dielectric film, and
- a copper film with a flat upper surface is provided at least in an upper portion of the conductive plug or between the conductive plug and the lower electrode of the capacitor.
A method for manufacturing a semiconductor device, comprising the steps of:
- forming an impurity region by introducing impurities into a semiconductor substrate;
- forming an interlayer insulating film over the semiconductor substrate;
- forming a contact hole reaching the impurity region in the interlayer insulating film;
- forming a conductive adhesive layer covering a wall surface of the contact hole;
- forming a copper film on the interlayer insulating film and filling the contact hole with copper;
- forming a conductive plug by polishing the copper film by low-pressure chemical mechanical polishing (CMP) or electro chemical mechanical polishing (ECMP) to leave the copper film only in the contact hole;
- and
- forming, over the conductive plug, a capacitor constructed from a lower electrode, which is electrically connected to the conductive plug, a dielectric film made of a ferroelectric or a high electric on the lower electrode, and an upper electrode on the dielectric film.
A method for manufacturing a semiconductor device, comprising the steps of:
- forming an impurity region by introducing impurities into a semiconductor substrate;
- forming an interlayer insulating film over the semiconductor substrate;
- forming a contact hole reaching the impurity region in the interlayer insulating film;
- forming a first conductive adhesive layer covering a wall surface of the contact hole;
- forming a conductive plug by burying a conductive material in the contact hole;
- forming a copper film over the conductive plug and the interlayer insulating film;
- planarizing the copper film by low-pressure chemical mechanical polishing (CMP) or electro chemical mechanical polishing (ECMP);
- sequentially forming a lower electrode material film, a dielectric film made of a ferroelectric or a high dielectric, and an upper electrode material film in this order on the copper film;
- forming a capacitor by patterning the upper electrode material film, the dielectric film, and the lower electrode material film;
- and
- removing the copper film except for that formed under the capacitor.
Dependencies are inferred from the claim text.