Abstract:
By forming a buried nickel silicide layer (260A) followed by a cobalt silicide layer (261A) in silicon containing regions, such as a gate electrode of a field effect transistor, the superior characteristics of both silicides may be combined so as to provide the potential for further device scaling without unduly compromising the sheet resistance and the contact resistance of scaled silicon circuit features.
Abstract:
By combining a respectively adapted lattice mismatch between a first semiconductor material (4, 104) in a channel region (112) and an embedded second semiconductor material (9, 109) in an source/drain region (110) of a transistor, the strain transfer into the channel region (112) is increased. The lattice mismatch may be adapted by a biaxial strain in the first semiconductor material (4, 104). The lattice mismatch may be adjusted by a biaxial strain in the first semiconductor material (4, 104). In particular, the strain transfer of strain sources including the embedded second semiconductor material (9, 109) as well as a strained overlayer is increased. According to one illustrative embodiment, regions of different biaxial strain may be provided for different transistor types.
Abstract:
By forming a portion (209A, 309A, 409A) of a PN junction (209, 309, 409) within strained silicon/germanium material (207, 307, 407) in SOI transistors (200, 300, 400) with a floating body (221, 321) architecture, the junction leakage may be significantly increased, thereby reducing floating body effects. The positioning of a portion (209A, 309A, 409A) of the PN junction (209, 309, 409) within the strained silicon/germanium material (207, 307, 407) may be accomplished on the basis of implantation and anneal techniques, contrary to conventional approaches in which in situ doped silicon/germanium is epitaxially grown so as to form the deep drain and source regions. Consequently, high drive current capability may be combined with a reduction of floating body effects.
Abstract:
By recessing (112D, 212D) drain and source regions (114, 214), a highly stressed layer (118, 218), such as a contact etch stop layer, may be formed in the recess (112, 212) in order to enhance the strain generation in the adjacent channel region (104, 204) of a field effect transistor (100, 200). Moreover, a strained semiconductor material (230) may be positioned in close proximity to the channel region (104, 204) by reducing or avoiding undue relaxation effects of metal suicides (217), thereby also providing enhanced efficiency for the strain generation. In some aspects, both effects may be combined to obtain an even more efficient strain- inducing mechanism.
Abstract:
By forming a strained semiconductor layer (117, 217) in a PMOS transistor (110, 210), a corresponding compressively strained channel region (11 IA) may be achieved, while, on the other hand, a corresponding strain in the NMOS transistor (120, 220) may be relaxed. Due to the reduced junction resistance caused by the reduced band gap of silicon/germanium in the NMOS transistor (120, 220), an overall performance gain is accomplished, wherein, particularly in partially depleted SOI devices, the deleterious floating body effect is also reduced, due to the increased leakage currents generated by the silicon/germanium layer (117, 127, 217, 227) in the PMOS (110, 210) and NMOS transistor (120, 220).
Abstract:
The introduction of a barrier diffusion material, such as nitrogen, into a silicon-containing conductive region, for example the drain and source regions (204, 205) and the gate electrode (208) of a field effect transistor, allows the formation of nickel silicide (211, 212), which is substantially thermally stable up to temperatures of 500 °C. Thus, the device performance may significantly improve as the sheet resistance of nickel silicide is significantly less than that of nickel disilicide.
Abstract:
By reconfiguring material (202, 302, 402) in a recess (210R, 310R, 410R) formed in drain and source regions (251, 351, 451) of SOI transistors (250, 350, 450), the depth of the recess (210R, 310R, 410R) may be increased down to the buried insulating layer (205, 305, 405) prior to forming respective metal suicide regions (254), thereby reducing series resistance and enhancing the stress transfer when the corresponding transistor element (250, 350, 450) is covered by a highly stressed dielectric material (203). The material redistribution may be accomplished on the basis of a high temperature hydrogen bake (211, 311) or an isotropic etch.
Abstract:
By appropriately orienting the channel length direction with respect to the crystallographic characteristics of a silicon layer (102), the stress-inducing effects of strained silicon/carbon material (109) may be significantly enhanced compared to conventional techniques. In one illustrative embodiment, the channel (103) may be oriented along the direction for a (100) surface orientation, thereby providing an electron mobility increase of approximately a factor of four.
Abstract:
A method [900] of forming an integrated circuit [100] and a structure therefore is provided. A gate dielectric [104]is formed on a semiconductor substrate [102], and a gate [106] is formed over the gate dielectric [104]. Shallow source/drain junctions [304,306] are formed in the semiconductor substrate [102]. A sidewall spacer [402] is formed around the gate [106]. Deep source/drain junctions [504,506] are formed in the semiconductor substrate [102] using the sidewall spacer [402]. A siliciding spacer [610] is formed over the sidewall spacer [402] after forming the shallow and deep source/drain junctions [504,506]. A silicide [604] [606] is formed on the deep source/drain junctions [504,506] adjacent the siliciding spacer [610], and a dielectric layer [702] is deposited above the semiconductor substrate [102]. Contacts are then formed in the dielectric layer [702] to the silicide [604][606].
Abstract:
By forming an implantation mask (220) prior to the definition of the drain and the source areas (208), an effective decoupling of the gate dopant concentration from that of the drain and source concentrations is achieved. Moreover, after removal of the implantation mask (220), the lateral dimension of the gate electrode (205) may be defined by well-established sidewall spacer (207) techniques, thereby providing a scaling advantage with respect to conventional approaches based on photolithography and anisotropic etching.