摘要:
A method for forming a dual gate oxide (DGO) structure begins by forming a first oxide layer (106) within active areas (110) and (112). A protection layer (108a) is then formed over the layer (106). A mask (114) is used to allow removal of the layers (106 and 108a) from the active area (110). A thermal oxidation process is then used to form a thin second oxide layer (118) within an active area (110). Conductive gate electrodes (120a and 120b) are then formed wherein the first oxide layer (106) and the protection layer (108c) are incorporated into the gate dielectric layer of an MOS transistor (122a). The transistor (122b) has a thinner gate oxide layer that excludes the protection layer (108c).
摘要:
A semiconductor dielectric (10) is formed by providing a base layer (12) having a surface. A thin interface layer (13) is formed at the surface of the base layer (12). The thin interface layer has a substantial concentration of both nitrogen and fluorine. A thermal oxide layer (14) is formed overlying the interface layer (13). A deposited dielectric layer (16) is formed overlying the thermal oxide layer (14). The deposited dielectric layer (16) is optionally densified by a thermal heat cycle. The deposited dielectric layer (16) has micropores that are misaligned to micropores in the thermal oxide layer (14) to provide enhanced features which the nitrogen/fluorine interface further improves the dielectric's features.
摘要:
An embodiment of the invention allows the reversing of the sequence of a stacked gate dielectric layer so that a thermal oxide overlies a CVD deposited oxide. A CVD dielectric (12) is first deposited to a desired thickness. Then a layer of silicon (16), either amorphous or polycrystalline, is deposited overlying the CVD dielectric, wherein this silicon layer is approximately one-half of the desired thickness of the final top oxide. The silicon layer is then thermally oxidized to form thermal oxide (18). This method of the invention allows the denser thermal oxide to be formed overlying the less dense CVD dielectric layer as desired to form a reverse dielectric stack.
摘要:
An annealed amorphous silicon layer is formed prior to forming field isolation regions when using in a LOCOS field isolation process. The annealed amorphous silicon layer helps to reduce encroachment compared to conventional LOCOS field isolation process and helps to reduce the likelihood of forming pits within a substrate compared to a PBL field isolation process. The annealed amorphous silicon layer may be used in forming field isolation regions that defines the active regions between transistors including MOSFETs and bipolar transistors. Doped silicon or a silicon-rich silicon nitride layer may be used in place of conventional materials. The anneal of the amorphous silicon layer may be performed after forming a silicon nitride layer if the silicon nitride layer is deposited at a temperature no higher than 600 degrees Celsius.
摘要:
A method for forming a gate dielectric (14b) begins by providing a substrate (12). A high K dielectric layer (14a) is deposited overlying the substrate (12). The dielectric layer (14a) contains bulk traps (16) and interface traps (18). A polysilicon gate electrode (20) is then patterned and etched overlying the gate dielectric (14a) whereby the plasma etching of the gate electrode (20) results in substrate plasma damage (22). A post gate wet oxidation process is performed between 750.degree. C. and 850.degree. C. to reduce plasma etch damage and trap sites (16, 18) in order to provide an improved gate dielectric (14b). Source and drain electrodes (30) are then formed within the substrate and laterally adjacent the gate electrode (20) to form a transistor device having more consistent threshold voltages, improved subthreshold slope operation, reduced gate to channel leakage, and improved speed of operation.
摘要:
An integrated circuit (10) is formed using jet vapor deposition (JVD) silicon nitride. A non-volatile memory device (11) has a tunnel dielectric layer (27) and an inter-poly dielectric layer (31) that can be formed from JVD silicon nitride. A transistor (12,13,40) is formed that has a gate dielectric material made from JVD silicon nitride. In addition, a passivation layer (47) can be formed overlying a semiconductor device (40) that is formed from JVD silicon nitride.
摘要:
A semiconductor dielectric (10) is formed by providing a base layer (12) having a surface. A thin interface layer (13) is formed at the surface of the base layer (12). The thin interface layer has a substantial concentration of one of either nitrogen or fluorine. A thermal oxide layer (14) is formed overlying the interface layer (13). A deposited dielectric layer (16) is formed overlying the thermal oxide layer (14). The deposited dielectric layer (16) is optionally densified by a thermal heat cycle. The deposited dielectric layer (16) has micropores that are misaligned to micropores in the thermal oxide layer (14) to provide enhanced features.
摘要:
This disclosure reveals a manufacturable and controllable method to fabricate a dielectric which increases the device current drive. A nitrogen-containing ambient is used to oxidize a surface of a substrate (10) to form a nitrogen-containing dielectric (12). Then a fluorine-containing specie (F) is introduced, preferably through implanting, into a gate electrode (20) overlying the nitrogen-containing dielectric. The fluorine is then driven into the underlying nitrogen-containing dielectric. A fluorinated nitrogen-containing region (14') is expected to form at the interface between dielectric (12') and substrate (10). The interaction between fluorine and nitrogen increases the peak transconductance as well as the transconductance at a high electric field for the dielectric. Therefore, the overall current drive is increased by this approach.
摘要:
Nitrogen is piled-up at a top interface of a gate dielectric layer by a process of the present invention. A gate dielectric layer (14) is formed on a substrate (12). A buffer layer (16), such as polysilicon, is formed on the dielectric layer. A nitrogen source layer (18), such as oxynitride, is formed on the buffer layer. The device is annealed to drive nitrogen from the source layer through the buffer layer and to an interface (15) between the polysilicon and the dielectric, resulting in a high nitrogen concentration at this interface. A nitrogen concentration may also be achieved at an interface (13) between the dielectric layer and the substrate.
摘要:
The reliability of integrated circuits fabricated with trench isolation is improved by increasing the thickness of the gate dielectric overlying the trench corner. After the trench isolation region (40, 56) has been formed a thin layer of silicon dioxide (44) is chemically vapor deposited over the trench isolation region (44) and the adjacent active region (23). A transistor gate electrode (46) is subsequently formed over the thin layer of silicon dioxide (44). The thin layer of silicon dioxide (44) increases the thickness of the gate dielectric that lies between the transistor gate electrode (46) and the trench corner, and therefore the breakdown voltage of the gate dielectric at the trench corner is increased.