摘要:
A method is provided for backside processing a semiconductor wafer (10) including applying a polymer based protective coating (16) on the wafer, depositing a barrier layer of ceramic (18) on the protective coating, and coating the ceramic layer with a thermoplastic based adhesive (20). Thereafter, the wafer (10) is bonded to a perforated substrate (22) and then lapped and polished to a desired thickness and patterned with an etch mask. A high temperature plasma etching process is then used to etch via holes in the wafer (10). After etching and subsequent backside processing, the adhesive layer (20) is dissolved in acetone to separate the wafer (10) from the substrate (22). The protective coating (16) is then dissolved with a solvent to separate the ceramic layer (18) from the finished wafer (10).
摘要:
Apparatuses (10, 100), and methods of using same, for the simultaneous thinning of the backside surfaces of a plurality of semiconductor wafers (W) using a non-crystallographic and uniform etching process, are described. The apparatuses (10, 100) include a fixture (12, 102) having a plurality of horizontal receptacles (14, 16, 18, 20, 104, 106, 108, 110) for receiving the semiconductor wafers (W). The loaded fixtures (12, 102) are then immersed into an etchant solution (36, 146) that is capable of isotropically removing a layer of semiconductor material from the backside surface of the semiconductor wafers (W). The etchant solution (36, 146) is preferably heated to about 40° C.-50° C. and constantly stirred with a magnetic stirring bar (48, 158). Once a sufficient period of time has elapsed, the thinned semiconductor wafers (W) are removed from the etchant solution (36, 146). The apparatuses (10, 100) are capable of simultaneously thinning several semiconductor wafers (V) down to a final thickness of about 25 &mgr;m.
摘要:
A method for determining the etch depth of a gate recess (26) in an InP based FET device (10). The source-drain, current-voltage (I-V) relationship is monitored during the etching process. As the etch depth increases, a kink is formed in the linear portion of the I-V relationship. When the kink current reaches a desired value, the etching is stopped. The kink current is a strong function of etch depth, so small differences in etch depth can be easily targeted. By controlling the etch depth, the characteristics of the transistor can be reproducibly controlled and optimized.
摘要:
An enhancement mode FET device (10) that employs a strained N-doped InAlAs charge shield layer (22) disposed on an intrinsic InAlAs barrier layer (20). A gate metal electrode (38) of the FET device (10) is controllably diffused through a recess (36) into the shield layer (22) to the barrier layer (20). The resulting enhancement mode device (10) provides an excellent Schottky barrier with a high barrier height that inhibits undesirable surface depletion effects through charge shielding by the shield layer (22) in the regions between the recess edge and the gate metal. Minimizing surface depletion effects makes the device more robust by making the surface less sensitive to processing conditions and long-term operation effects.
摘要:
A method of manufacturing a HEMT IC using a citric acid etchant. In order that gates of different sizes may be formed with a single etching step, a citric acid etchant is used which includes potassium citrate, citric acid and hydrogen peroxide. The wafer is first spin coated with a photoresist which is then patterned by optical lithography. The wafer is dipped in the etchant to etch the exposed semiconductor material. Metal electrodes are evaporated onto the wafer and the remaining photoresist is removed with solvent.
摘要:
A single-layer, metal-insulator-metal capacitor, a monolithic microwave integrated circuit including such capacitors, and a process of fabricating such capacitors. The capacitor has a single layer of insulating material between two metallic layers. At least one of the metallic layers has rounded corners, reducing the electric field at the corners, and so lessening the likelihood of breakdown. In one preferred embodiment, each metal layer has rounded corners. The capacitors can be fabricated by an optical lithographic process.
摘要:
A field effect transistor with a double sided airbridge comprises a substrate containing a conductive region and source, drain and gate electrodes disposed on the substrate. The gate electrode has a finger portion with a first end secured to the substrate between the source and drain electrodes and a second end, and a double sided airbridge portion flaring outwardly from the second end and having opposed first and second extremities. A first gate pad is disposed on said substrate outwardly from the source electrode and is connected to the first extremity. A second gate pad is disposed on said substrate outwardly from the drain electrodes and is connected to the second extremity. The gate pads serve to support the airbridge gate finger so as to reduce stress on the gate finger. The first and second gate pads receive and transmit signals through the airbridge and to and from the gate finger.
摘要:
A common source, bi-directional microwave amplifier is described. More particularly, the present invention is a microwave, common source, bi-directional amplifier that includes a first amplification path and a second amplification path wherein the signal directional flow is controlled through the selective biasing of the first amplification path and the second amplification path. Each amplification path is designed to optimize desired performance. For signal flow through the first amplification path, the first amplification path is biased-on and the second path is biased-off. For signal flow through the second amplification path, the second amplification path is biased-on and the first path is biased-off.
摘要:
In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).
摘要:
An aluminum alloy bicycle frame includes a set of tubes and a set of joint members for connecting the tubes, each of the joint members having a tubular joining portion. Each of the tubes has an externally threaded end provided with adhesive glue, and the tubular joining portion of each of the joint members has a threaded inner face provided with adhesive glue. The externally threaded ends of the tubes are respectively screwed into and adhered to the tubular joining portions of the joint members. This frame has strong joints which are clean and smooth in appearance, without requiring a high degree skill or unusually expensive materials.