| 摘要 |
<p>The invention relates to a process for determining the carrier concentration in a semiconductor by applying between an ohmic contact and a rectifying contact formed on said semiconductor, a d.c. voltage resulting in a reverse bias Udc, and two periodic excitation signals having the frequencies Φ1 and Φ2, respectively. The process can be characterized in that Φ1 is bigger than Φ2, such that Φ1, Φ2, their difference (Φ1-Φ2) and their sum (Φ1+Φ2) are in the same order of magnitude, selecting two components from the electronic response of said semiconductor to the excitation, the first component being the electrical response to said frequency Φ1 and Φ2 and the second component being a first order intermodulation product of one of Φ1 and Φ2, and determining said carrier concentration by simultaneous, parallel analysis of said first and second components. The invention relates further to an apparatus for determining the carrier concentration in a semiconductor comprising a semiconductor sample having an ohmic contact and a rectifying contact; means for applying a d.c. voltage between said contacts, resulting in a reverse bias Udc, and two periodic excitation signals having the frequencies Φ1 and Φ2 respectively; oscillators to generate said periodic excitation signals; means for generating reference signals; means for amplifying two components selected from the electronic response of said semiconductor to the excitation, the first component being the electrical response to said frequency Φ1 or Φ2, and the second component being a first order intermodulation product of one of Φ1 and Φ2; and two phase-sensitive rectifiers for rectifying said selected two a.c. components.</p> |
